[BUG][PLAYER] Swimmer-Drowner-Bomber physics bugs.

[namida]

The general setup for these cases: Assign a bomber such that (a) the lemming ohno'es, and (b) the lemming falls into water before exploding.

As far as I'm aware, the bomber can be substituted with a stoner. I haven't tested this, but can't think of any reason why it wouldn't work. I have confirmed that the nuke can be used for this, it doesn't need to be an actual bomber skill.

First, see what happens when the above is done with no further steps. The ohno'er becomes a drowner, and drowns.

Now, try assigning a swimmer to the ohno'er before they hit the water (you can't do this during the ohno, it must be done before assigning the bomber). Notice how instead of drowning (since swimmers can't drown), they continue falling to the bottom of the water, exploding when appropriate. This part, IMO, is fine.

The bug - in general (and this part itself isn't a bug), you can assign a swimmer to a mid-drowning lemming to save him. However, you can do this even when the above bomber hits the water. Becuase the lemming was no longer going to explode, you've now got a fully functional lemming again. Given that a non-drowning but has-swimmer ohnoer will not start swimming, and cannot be saved by water, I feel this is a bug.

I'm not entirely sure what the best resolution for it is, though. Possibilities are:
a) Ohnoers always ignore water, instead of just if they're swimmers.
b) Ohnoers always drown, even if they're swimmers.
c) Specifically prevent the above case - either the swimmer can't be assigned to the drowner in this case, or upon making the assignment the lemming immediately explodes.

I think B might be the most logical course of action here. A feels less natural, while C means we're introducing a specific new rule for an edge case instead of slightly tweaking an existing one - in a way that should have very little if any side effects - to cover the edge case better.

Related thing to check: Do ohnoer-disarmers falling onto traps also avoid exploding? I suspect not - my first prediction is that they'll get eaten by the trap; though "they ignore the trap and explode" is also possible. That's a much more obvious case and I think Nepster would have thought of this one - if I didn't think of it myself when initially implementing the disarmer, which itself is fairly likely.

Here's a level and a replay that illustrates this bug (and cannot be solved without it - activated via the nuke, rather than a bomber skill, in this case).

[IchoTolot]

I would say b) is the most logical case for me. An Oh-Noer uses his hands to explode --> therefore cannot swim if that makes sense.

a) seems very weird for me when they just fall through the water. This would be my least preferred case.

As a result this also seems like the bug for me:

Now, try assigning a swimmer to the ohno'er before they hit the water (you can't do this during the ohno, it must be done before assigning the bomber). Notice how instead of drowning (since swimmers can't drown), they continue falling to the bottom of the water, exploding when appropriate. This part, IMO, is fine.

Normally traps catch any type of falling Lemming regardles if he is a disarmer or oh-noer.

[Proxima]

I would prefer (c). To my mind, an ohnoer is already a dead lemming, and seeing the ohno animation is just flavour. They shouldn't be available for assigning skills. (Can you assign climber to a normal walking ohnoer?)

[namida]

I would prefer (c). To my mind, an ohnoer is already a dead lemming, and seeing the ohno animation is just flavour. They shouldn't be available for assigning skills. (Can you assign climber to a normal walking ohnoer?)

You cannot assign any skill to an ohnoer. This situation arises because the ohnoer hits the water and becomes a drowner, which you can assign one skill to - a swimmer. Assigning a swimmer to a drowner, causes them to transition from drowning to swimming immediately.

[Dullstar]

A fourth possibility might be to make OhNoers instantly explode/stone on contact with water. Certain situations already skip the OhNo animation, it avoids lemmings falling through water, and avoids a specific case in which a drowner cannot be assigned a swimmer.

[namida]

Certain situations already skip the OhNo animation

While this is true, there is currently no situation in which the OhNo animation is interrupted mid-way with an immediate explosion. All situations currently either skip the ohnoer entirely, or have the full ohno'ing animation. Not that this outright means that isn't a possible solution - I actually think that's not a bad idea - but just that there isn't a precedent here based on that.

[ccexplore]

Interesting corner case.  IIRC in DOS Lemmings, ohno-ers will ignore water and pretty much everything else except terrain.  It cannot transition to anything else except exploding for good at the end of its short lifetime.

Personally I'm okay with A).  I think it's actually already a little strange and inconsistent that the swimmer+ohno-er will effectively ignore water rather than become a swimming lemming like how it'd normally interact with regular lemming, even though the non-swimmer+ohno-er will react to water and drown (and effectively canceling the impending explosion the ohno-er is supposed to guarantee, even though in that case at least it still dies).  It is more consistent if it just plain ignores water always.  Of course, that may be what happens in DOS Lemmings, but it's possible in NeoLemmix maybe the ohno-er can already interact with many other object trigger types in the level?  In which case ignoring water might then become the odd man out in terms of consistency?

If you do decide that ohno-er can transition to other things, then you have a decision as to whether it should still always be destined to explode, or instead you are legitimizing ways to basically cancel an explosion.  I prefer no canceling of explosions, in which case I'd prefer that however you want to deal with transitions out of ohno and further, the lemming must still explode no matter what at the end of 16 or so frames that the ohno-er normally lasts, even if by then it has changed far away from ohno-ing.  Maybe through a new special internal state marking the lemming as destined to explode immediately no matter what once that 16 or so counter runs out.  Admittedly, maybe this will feel as strange as allowing cancelation of explosions.  So again maybe A is the simplest way out.

[edit: fix incorrect number of frames; 48 is the effective max fall distance]

[ccexplore]

I'll add that I can probably accept B as well.  If you consider that conceptually the lemming is already broken/sick/malfunctioning at the point of ohno-ing, you can argue that it can no longer manage to swim even if it has the skill, so it's fine if it always drowns no matter what at that point.  That is if you feel strongly that the lemming should still react to water and transition out of ohno rather than ignore it.

[namida]

Unless Lemmix is not replicating DOS Lemmings accurately, ohnoers will drown in DOS Lemmings.

In both DOS and NL, ohnoers can interact with exits. This is an intentionally accepted behaviour in NL.

[Strato Incendus]

So at last this seems to be the NeoLemmix equivalent of a trick I've repeatedly outlined about Lemmings Revolution: In LR, Oh-Noers can't splat, so you can use the Oh-Noer to have a lemming survive a drop that would kill him otherwise, even if you don't have a Floater. Then, you assign a Builder to the Oh-Noer standing on the ground, and he "forgets" that he was about to explode.

In NeoLemmix, this never comes up, because Fallers explode instantly when assigned a Bomber or Stoner, and on-the-ground Bombers that are made to fall by removing the terrain under them at just the right moment, they can never fall a distance even remotely close to splat height before exploding. But of course, they can drop into water if they're close enough already.

I'm not entirely sure what the best resolution for it is, though. Possibilities are:
a) Ohnoers always ignore water, instead of just if they're swimmers.
b) Ohnoers always drown, even if they're swimmers.
c) Specifically prevent the above case - either the swimmer can't be assigned to the drowner in this case, or upon making the assignment the lemming immediately explodes.

First of all, obviously there's a part of me now that wants to construct a level around enforcing the use of this stupid corner case . But our goal in general should obviously be to make NeoLemmix as logically consistent as possible.

With that said, and with that in mind: The current behaviour actually is somewhat consistent: If you know that lemmings can only have one state at a time, Oh-Noer or Drowner, and the Drowner "overwrites" the Oh-Noer, then it's not that surprising that the Swimmer offers a way to return from the Oh-Noer, given that we know the Swimmer can let a lemming return from being a Drowner.

b) is consistent with the Disarmer behaviour when falling into a trap; however, I'm not sure IchoTolot's explanation "he's using his hands to oh-no" necessarily works to make this apparent to a new player. Mainly because the Disarmer doesn't really need to use his hands for being a Faller, yet the trap still kills him. Sure, the Disarmer lands on the trigger, but the Disarmer always needs to step onto the trigger to disarm the trap anyway; it's not something he can do "in advance" before even moving into what would be the "danger zone" for any other lemming.

I coud offer a similar "in-flavour explanation" for the current behaviour:

A Bomber uses some sort of explosive to bomb himself, and most likely, that explosive requires a fuse. This was even more apparent with timed Bombers, of course, but unless he explodes in mid-air, the Oh-Noer animation implies the lemming still needs to do something in order to activate the bomb.

When he drops into a water pond at the last moment, the water extinguishes the fuse, and therefore, the lemming can't actually explode (even if he wanted to). He will simply start drowning, like any other lemming would, and consequently, you could save him from drowning like any other lemming. However, there's no need to save him from oh-noing anymore, because the water actually does that, and it makes total sense - both mechanically and flavourwise .

[namida]

When he drops into a water pond at the last moment, the water extinguishes the fuse, and therefore, the lemming can't actually explode (even if he wanted to). He will simply start drowning, like any other lemming would, and consequently, you could save him from drowning like any other lemming. However, there's no need to save him from oh-noing anymore, because the water actually does that, and it makes total sense - both mechanically and flavourwise .

This would only be consistent if (a) an already-existing swimmer also cancelled the exploding upon hitting water, and (b) it was not possible to assign a bomber to a lemming while swimming. Not to mention, that explanation doesn't make so much sense for stoners - I haven't tested, but I'd believe everything mentioned here is equally applicable to them, based on that the ohnoer is the same state either way, just with a flag that determines whether it explodes or stones when finished.

[ccexplore]

Wow, how embarrassing, i can't believe I remembered it so wrong.

I do remember that a lemming whose exiting could oh-no, but I wasn't sure if the oh-no could then exit again or not, and thought maybe it couldn't.  But I just checked and that's not the case.

I guess they allowed it because most object triggers either have no meaningful impact to the lemming, or it'll kill them anyway.  Though the exiter case is already kind of weird.  I frankly don't know if that feels right to me, but I guess it's too late to do anything about that.

From looking at the DOS Lemmings code (ie. not just Lemmix, the actual DOS Lemmings assembly code), what happens is that the ohno processing ends by jumping into another part of code that was written for faller handling, which mainly checks for level bottom boundary, but then does end with interactive object detection and procesing.  It definitely saves a few bytes to jump to code already written rather than repeating it for ohno, but it's impossible to know whether they are fully aware that in doing so, this also allows interactions with all objects for ohno-ers.

Given this is the precedent, and at the same time, we most probably don't want to introduce any changes that would actually make it possible to fully cancel an exploding lemming (ie. we probably don't want them be able to turn swimmer and completely skip dying), I guess B (always drown) would then be the most consistent choice.  The ohno lemming will interact with the water just like it apparently can interact with anything, but it's sick and cannot do swimming like it normally could.

[ccexplore]

To be clear, I'm assuming we don't want to allow canceling an explosion through ohno -> swimmer, but personally I don't care one way or another.  I'm mainly assuming that the ability to cancel an explosion may be too backroute-prone, but this admittedly seems to be a pretty specific setup, and it also seems like there is no clear advantage to waste a bomber just to make this behavior happen, when you could simply not assign bomber to start with.  So maybe it's not even that big a deal from a backroute-prone perspective.  About the only thing interesting you can do puzzle-wise with explosion-canceling that I can think of, is maybe to save some lemmings from a nuke.  This seems tricky to exploit generally, but admittedly could probably be exploited in some cases.

Given that ohno-ers effectively can have the impending explosion be canceled today by all manners of objects, the fact that some cases can then lead the lemming to permanently survive is perhaps not all that strange, if you already accept the canceling as fact.  After all, exiting is also a form of permanent survival and we've allowed that for ohno-ers, apparently!  So in that perspective, maybe the right thing is actually to allow an already-assigned-swimmer lemming to actually go swimming when they hit water during ohno.  After all, that's how they were meant to interact with water, and we allow interactions with water.  But that is probably too backroute-prone to introduce such behavior now when currently they die?

[Strato Incendus]

This would only be consistent if (a) an already-existing swimmer also cancelled the exploding upon hitting water, and (b) it was not possible to assign a bomber to a lemming while swimming.

Oops... How could I, the creator of the infamous "Dark fate of Atlantis" from Paralems, have forgotten about that?

In that case, I think it would actually make more sense for Oh-Noers falling into water to instantly explode if they are Swimmers - given that Swimmers who are assigned Bombers or Stoners also perform the skill immediately.

Yes, that would require stopping the Oh-No animation in the middle, which would be a new thing and probably somewhat challenging to program.

However, without that, we can quickly imagine a new corner case by adding another corner to the scenario, and ccexplore already hinted at it:

After all, exiting is also a form of permanent survival and we've allowed that for ohno-ers, apparently!

Let's say, you have a Swimmer that is assigned a Bomber while standing on terrain, it starts to Oh-No, then drops into the water - right above the exit, which is also placed in the water. The Swimmer-Oh-Noer drops right onto the trigger of the exit.

Non-Swimmers can't access exits in water, even if they fall into them straight from above, just like Non-Floaters / Non-Gliders can't fall into an exit in mid-air.
Swimmers and Oh-Noers, however, both can access exits.
This lemming is both a Swimmer and an Oh-Noer, so there is absolutely no reason why it should drown, and two reasons why it should enter the exit.

[IchoTolot]

It still feels right to me that the oh-noer should not be a special case that doesn't react to water at all. So I think a reaction should be there.

Now is the question: Explosion, swimming or drowning?

Swimming I think should be out as that would recycle the Lemming. That seems to be in the minds of most people here.

And between an instant explosion (which seems very weird to me) and the drowning I still think the drowning is the answer even if the Lem is a swimmer. The Oh-Noer I think should cancel out the other permanent skills. Also this would create a completely new type of special case where an Oh-Noer can be cut short for a faster explosion.

Let's take the following line of thinking under the basic assumption "Swimming should be out of the question as that would recycle the Lemming":

1.) An oh-noing disarmer should not be able to disarm traps anymore, although he can be eaten by them. (A oh-noing climber also stops climbing for example)

2.) A swimmer being assigned a bomber explodes instantly, but this is a no Oh-No case and he does not swim anymore right after the assignment and just explodes.

3.) In our problem we have the case that the Lemming is already Oh-Noing and does not already swim.

4.) We have situation 3.) now and under the assumption "Swimming should be out of the question as that would recycle the Lemming" the Lemming should NOT behave after 2.) as that would be the exact reaction of a swimmer in water, therefore impling that he briefly switched to swimming in order to interrupt the Oh-Noing to explode instantly.

5.) If the Lemming should not behave like a swimmer that therefore renders out swimming (after the basic assumption) and exploding (as that would imply that he switch to swimming), he should behave like every other Oh-Noing and simply drown, what would be consistant with 1.) on top of that: A oh-noing swimmer should not swim anymore, but again should be "eaten" by the water.

As a result, I would still go with b.) "Ohnoers always drown, even if they're swimmers", as this avoids new special cases where Oh-Noers can prematurely explode and does not have any kind of hint that the Lemmings was recycled from an Oh-Noer to a Swimmer, even if the Swimmer explodes instantly and does not swim.

[Strato Incendus]

I think the entire discussion basically revolves around this:

The Oh-Noer I think should cancel out the other permanent skills.

That's precisely what came to my mind when I thought about what the suggestions made in this thread would imply. But that also means we need to think about whether this applies to all permanent skills we have so far.

1.) An oh-noing disarmer should not be able to disarm traps anymore, although he can be eaten by them. (A oh-noing climber also stops climbing for example)

Indeed, Oh-Noers can be killed by traps - I've found out by accident on my Lemmicks level "The Eye of the Needle", where I wanted to stone right between a teleporter and one of those Space "shooting bird" traps. Even though I lost the Stoner from the skill panel due to assigning it, the lemming still got shot by the trap rather than turning to stone.

Since Oh-Noers can only get onto a trap trigger by falling, and falling into a trap kills Disarmers, it makes sense for oh-noing Disarmers to die to traps as well. However, this doesn't necessarily imply the Disarmer loses the skill due to oh-noing, because he would also die if he simply fell onto the trap trigger regularly.

Floaters and Gliders can't oh-no, and coincidentally, Oh-Noers can neither float nor glide, because they never reach splat height anyway before exploding, as I've repeatedly outlined in this thread. So we never actually see whether they "lose" the skill, unless you'd want to argue that floating or gliding lemmings already open up their parachutes very early during a drop, i.e. even before a regular lemming would reach splat height - and Oh-Noers don't.

With Climbers, there's an important difference to what you've outlined here:

The Climber stops climbing, yes, but it doesn't "lose" the Climber skill in the sense that it doesn't suddenly fall off the wall.

That's actually what Shimmiers used to do when they were assigned Bombers, and then we changed it so that Shimmiers also explode instantly. It was the only case where I had to slighlty adapt a level to changed Shimmier behaviour, but I was happy about that, because any lemming without ground under his feet should explode instantly. In the Climber's case, one could argue that his feet are pointing towards the wall, hence he oh-noes, but Shimmiers don't. Consequently, if we were to introduce the Magno-Booter from Lemmings 2, that lemming should oh-no when turned into a Bomber, even if he's currently dangling from the ceiling. (L2 circumvents this problem by not enabling the player to assign skills to upside-down Magno-Booters at all, but I think that makes the skill very limited in its application.)

Also, on a purely visual level: Athletes that are assigned a Bomber or Stoner don't suddenly return to having green hair and blue clothes when they oh-no...

Instead, with the Climber remaining in its place when oh-noing and sort-of "standing in the air" while doing it, one could argue that Swimmers should do the same, i.e. "stand" on top of the water area an finish the oh-no-animation plus the explosion, rather than continuing to fall.

[IchoTolot]

The Climber stops climbing, yes, but it doesn't "lose" the Climber skill in the sense that it doesn't suddenly fall off the wall.

That's because the climber is actually placed 1 pixel inside the wall. The Oh-Noer is standing inside the wall and is in no need of the climbing ability.

Instead, with the Climber remaining in its place when oh-noing and sort-of "standing in the air" while doing it, one could argue that Swimmers should do the same, i.e. "stand" on top of the water area an finish the oh-no-animation plus the explosion, rather than continuing to fall.

That would disarm the "Simmers should stand on water" argument, as the climber Oh-Noer stands on solid ground on the most outer wall column.

Floaters and Gliders can't oh-no, and coincidentally, Oh-Noers can neither float nor glide, because they never reach splat height anyway before exploding, as I've repeatedly outlined in this thread. So we never actually see whether they "lose" the skill, unless you'd want to argue that floating or gliding lemmings already open up their parachutes very early during a drop, i.e. even before a regular lemming would reach splat height - and Oh-Noers don't.

If a glider or floater digs and before turning into a faller the digger is given a bomber in mid-air, he turns into an Oh-Noer and falling like a normal lem ignoring the glider/floater ability to fall slower/glide forward hinting at that the lemming has lost the skill --> supporting my argument for the drowning swimmer in my last post:

If the Lemming should not behave like a swimmer that therefore renders out swimming (after the basic assumption) and exploding (as that would imply that he switch to swimming), he should behave like every other Oh-Noing and simply drown, what would be consistant with 1.) on top of that: A oh-noing swimmer should not swim anymore, but again should be "eaten" by the water.

As that would then not only be consistent with disarmers and climbers, but also floaters and gliders.

[ccexplore]

The proposal that ohnoers should lose all permanent skills sound good to me and is already pretty close to how things work currently.  It goes along with my suggested concept that the ohno lemming is sick and therefore not capable of most actions at that time, just like you also can't assign skills to it.

[ccexplore]

Actually, I think we are kind of missing the point now that I review namida's original message more carefully.  If I understand correctly the problem considered most severe, is specifically that you can currently do ohno -> drown -> assigned swimmer now and it swims (and recycle the lemming from impending death, to borrow IchoTolot's words).  Proposal B by itself actually is meaningless for this case--you have to specifically remember that the drowning lemming was transitioned from an ohno lemming, so that either the attempted subsequent swimmer assignment is disallowed, or that it is allowed but does not let the lemming swim.

In other words, it seems like you'd need both B and C actually, if I understand the situation accurately.

[IchoTolot]

Actually, I think we are kind of missing the point now that I review namida's original message more carefully.  If I understand correctly the problem considered most severe, is specifically that you can currently do ohno -> drown -> assigned swimmer now and it swims (and recycle the lemming from impending death, to borrow IchoTolot's words).  Proposal B by itself actually is meaningless for this case--you have to specifically remember that the drowning lemming was transitioned from an ohno lemming, so that either the attempted subsequent swimmer assignment is disallowed, or that it is allowed but does not let the lemming swim.

In other words, it seems like you'd need both B and C actually, if I understand the situation accurately.

You are right there, this currently only cover the case the swimmer was assigned before. In the uncovered case assigning a swimmer to that specific lem should be prohibited. General rule could be for all Oh-Noer cases: No more skill assignments to a lemming that was already an Oh-Noer --> Oh-Noers are untouchable.

So in the end it would be: b + c (in the no-assignment case)

[Simon]

Beautiful corner case, very nice find.

(c) is good, prevent assignment to whoever has been oh-noer. Reasoning: Oh-noers can already exit, therefore oh-noers should drown and trigger traps.

Oh-noers should not descend to the bottom of the well, bypassing all water, and bomb holes in the bottom.

Need (b) too, apparently, ignore swimming ability when oh-noer enters water.

-- Simon

[Strato Incendus]

@IchoTolot: Thanks for the explanation about the positioning of the Climber; I didn't know it was actually treated as placed inside the wall.

How about my - initially somewhat jokingly uttered - idea of recolouring Oh-Noers to the regular colour scheme, then (i.e. green hair and blue clothes, or whatever the currently-used sprites standard look is)?

That would make it visually clear for every player that all athletic skills have been lost to the Oh-Noer. More than that, all trap animations we currently have are only for regularly-coloured lemmings anway. So it would make sense to have the same behaviour for Oh-Noers. Only Drowners that have not been Oh-Noers before should keep their athlete look, because obviously, a regular Drowner (no matter if a regular Walker or, e.g., a Climber) can still be assigned a Swimmer, and would then also continue to have all its other athletic skills.

[namida]

To be honest - I'm quite liking this "ohnoers lose their permanent skills" suggestion. Not saying it's a sure thing yet, but I'm heavily leaning towards that one.

[Strato Incendus]

There is only one flaw in this logic, I just realised:

Blockers still function as Blockers while oh-noing. I'm not sure how many people are aware of this - I remember trying to build a level for Lemmicks with the permanent Blockers gimmick, where the player was supposed to use the brief oh-no phase to sneak past the Blocker. But also, someone of those who LPed my packs (I honestly don't remember who) tried to sneak past an oh-noing Blocker. This doesn't work, however - lemmings still turn around on the "elbows" of the Oh-Noer, so to say.

Of course, one could refute this by saying that Blockers don't count as permanent skills - since they can be cancelled with Walkers or by removing the terrain under them - but it would still go against the idea of "an Oh-Noer can't do anything else".

In most cases where they are not freed by Walkers or by removing the terrain under them, Blockers are indeed pretty much permanent, they're just not athletic skills.

I'm also thinking about this with regard to the new NeoLemmix Introduction Pack that IchoTolot is working on - because I think it does precisely that, calling Blockers "permanent".

So when this pack receives a level specifically about oh-noing (aside from the already existing nuke level), one would have to think carefully about the correct wording ("loses all permanent skills" vs. "loses all athletic skills" etc.).

[IchoTolot]

You are right that blockers would be the odd one out here.

They are not athletic, but I think even if I used the word permanent it doesn't mean the same permanent as the permanent skills (I know how this sounds ). The blocker is permanent as long as he is standing on solid ground, or has been assigned a walker or bomber. These skills or the loss of the solid ground will make him loose that ability (the bomber still after the Oh-Noing). I couldn't think of another wording other than "permanent as long as X" to describe the blocker. Athletic skills so far are "more permanen"t and losing them usually means the lemming dies in the process.

I still think even with that one not fitting blocker case that the b + c approach ("ohnoers lose their permanent skills") fits best here.

How about my - initially somewhat jokingly uttered - idea of recolouring Oh-Noers to the regular colour scheme

I would be fine with that, as long as style themed recolorings are preserved.

[ccexplore]

Blocker is not a true permanent skill.  A true permanent skill means the lemming never loses it (with the exception proposed for ohno).  You have no need to assign a lemming the same permanent skill more than once.  Blocker is decidedly not like that.  Conversely, you can do things like arrange for a miner to mine forever on a slope with strategically placed teleporter to make it loop.  The blocker is no more permanent than that miner is.  It's merely harder to transition out of blocker (compared to other skills) because the blocker doesn't move, does nothing to nearby terrain, and refuses most skill assignments.

If a blocker is a true permanent skill, I would expect that freeing it would cause it to block again (at no cost of skill assignment) at next opportunity, for example immediately after it finishes falling down.

Also, most (all?) permanent skills, by their permanence nature, means you can often assign them well ahead of time of when you actually need the skill take action.  Whereas your non-permanent skills take action immediately upon assignment.  If you assign a non-permanent skill too early, you likely end up wasting the skill because its action would be executed at the wrong location.

Anyhow, while I agree that maybe having ohnoers retain ability to block is probably not in spirit, in practice there'll be cases where it's not desirable for lemmings to be able to slip past the ohno-ing blocker, before it actually explodes and takes out whatever needs to be taken out.  I think there's a strong enough case of leaving this specific behavior alone given its history (ie. it's already like that all the way back to Lemmings 1) and practicality.

[namida]

I have implemented both ideas: Ohnoers lose their permanent skills (with the blocker special case preserved), and skills cannot be assigned to an ohnoer (even if he changes state again, such as to a drowner - which I believe was the only case in which it ever was possible to assign a skill to a former-ohnoer anyway, the old "non-fatal bombers" gimmick aside).