Okay, here's my detailed feedback:
General - A few of these levels have names that are identical to those from the original game. "Lemmings Lemmings Everywhere" and "The Boiler Room" are the first to come to mind. Not that I've never been guilty of doing that... xD
Fun 1-7 - I think you should fill these slots in with your own levels, just a thought. Don't have to be training levels, could just be really easy ones.
Fun 8 - A buried exit is a bit of a harsh start, even if it's visible where it is.
Fun 14 - The level isn't bad in itself, but I think it should be moved to a later position in the pack.
Fun 15 - Well you know my opinion on bomber-timing in general, but I especially think this is far too early a position for it. Recall that the original game didn't have any bomber timing until mid-Tricky.
Fun 16 - I like the design. It somewhat reminds me of Wimpy 20 / PSYCHO 8 from LPDOS.
Fun 19 - No real comments either way about this level (it's not bad, but it doesn't particularly stand out either), but a small challenge - try to beat it with only 1 builder (other skills staying as-is).
Fun 21 - I'm glad to see you moved this, the similarity to "Lemming Athletics" isn't so noticable when they're a few levels apart.
Fun 25 - This is a good level, but I'm not 100% sure about the placement of it - I think it would've been more suited to early Tricky.
Fun 26 - This level is one of the best examples of what I mean about builder-heavy levels. It probably would be a good level if these kind of levels were rarer, but as it stands, it's just one among many builder-overload levels.
Fun 27 - I already mentioned about solving it with just two skills; it's a good level though.
Fun 30 - I think this was a good level to finish Fun with.
Tricky 1 - ...and a good level to open Tricky with too.
Tricky 2 - Not a bad level, but I feel this repeat is far too close to the original version in the level order.
Tricky 3 - Another example of overreliance on builders.
Tricky 4 - This is quite a good level.
Tricky 5 - This is a very good level too, although as you might notice in my replay, it's easily possible to save far more than required. In fact, I would've probably saved close to 100% (not quite since I used a bomber, but close) if I'd paid more attention to the clock.
Tricky 6 - This was also a very good level, though maybe should've been placed a bit later.
Tricky 8 - Now, this is an example of a level that does use a lot of builders, but is still a good level, because there's plenty more to it than just "block off the crowd, build build build maybe use a basher build build, release crowd".
Tricky 9 - This is another example of one that uses builders but isn't bad - because it's quite short, and the thematic design makes it much less annoying.
Tricky 10 - This level is placed FAR too early in the pack. It is however a very good level.
Tricky 11 - Now this is another example of the kind of builder-heavy level that isn't so great.
Tricky 12 - And this is another example of the kind of builder-heavy level that
is good, although this is also another one that's too hard for its position. To be honest, I think this should've been a Mayhem level.
Tricky 14 - This is a pretty fun level.
Tricky 15 - Firstly, this is another excessive-building-to-the-point-it's-tedious level, and secondly, remember how I mentioned originally about "Lemming Athletics" and the level following it? You've got the same two levels' repeats in a row here too, just in the reverse order. I'd say move them a bit further away from each other too.
Tricky 18 - This level, and its repeat, are two of my favorite levels from this pack.
Tricky 20 - This was also a pretty good level.
Tricky 22 - This was also a pretty
great level, though maybe again a bit hard for the position.
Tricky 23 - This level is an example of one that is annoyingly heavy on builders, but at the same time, the parts of the level outside of the excessive building are actually pretty good.
Tricky 24 - This is FAR too hard for Tricky; but it is a great level.
Tricky 26 - Another mostly-builder level.
Tricky 27 - The new level here is quite good.
Tricky 29 - This is an almost perfect example of the builder-heavy levels.
Tricky 30 - Not a bad level, but it's too
easy for its position.
Taxing 1 - This is pretty good!
Taxing 2 - The big gap between the pillar coming from the top and the one with steel doesn't really add anything to the level; that aside it's pretty good.
Taxing 3 - This is a good level! I like the design, too.
Taxing 4 - This is also a good one.
Taxing 5 - Now, here's
another example of a level that uses builders a lot without being bad. This was actually the first level that gave me a lot of trouble.
Taxing 6 - This one wasn't so impressive...
Taxing 7 - Bomber timing. Yuck.
Taxing 8 - This one was good!
Taxing 9 - I don't remember this one, is it new? (It's not mentioned as new on your list) At any rate, it's another builder-heavy one with not much else to offer.
Taxing 10 - This isn't a bad level, though check my replay - the fire doesn't quite work as well as you expected, I think. Unless that was your intention.
Taxing 11 - Same goes here as for its earlier version.
Taxing 12 - This is a VERY good level.
Taxing 13 - Same goes as for the earlier version.
Taxing 14 - More bomber timing. >_>
Taxing 15 - This probably should be in Mayhem, but I thought it was a good level. Though this trick is a bit overused by now (not meaning by you as such, just in general in Lemmings levels).
Taxing 17 - I actually didn't find this one too bad.
Taxing 18 - This was another one that took me a while to work out. Not a bad level. And I LOVE the name.
Taxing 19 - I think this level took me the longest to solve out of the pack. It's pretty good.
Taxing 20 - This one was quite good too.
Taxing 21 - This level is EXCELLENT!
Taxing 22 - This one isn't really any harder than its earlier version...
Taxing 23 - This one took me quite a while to work out too! Nice level.
Taxing 24 - This is another case of a level that contains good parts, but is padded out with a lot of pointless building too. This level would be a lot better with the middle 1/3rd cut out.
Taxing 25 - This is a good level.
Taxing 26 - So is this.
Taxing 27 - And this.
Taxing 28 - And this.
Taxing 29 -
And this.
Taxing 30 - This, though, is far too easy for the final level of Taxing.
(On a side note, I think Taxing is by far the most well-made rank in your pack - sure it has a few duds, but the majority of the levels are really good.)
Mayhem 1 - This was a pretty good level, though you give (not require - this is a completely different matter here) far more builders than are nessecary.
Come on,
THIS. IS. MAYHEM!Mayhem 2 - Either this level is far too easy for Mayhem, or it has a
major backroute that I'm not sure how you missed. I'm guessing the latter, given the layout.
Mayhem 4 - Not a bad level (though why are you saying "by DMA Design" on a fanmade level...?), but it's too easy for Mayhem.
Mayhem 5 - As I said before, this level is horrible... more excessive building while blockers hold the lemmings back, and a completely unexpected trap at the end to boot (yes, hidden traps can be good, but this is a case of where it's just annoying - it is kind of hard to explain the difference).
Mayhem 6 - Okay, so I wasn't thinking of Mayhem 5 and Mayhem *6* with my comment before. However, this is a pretty good level, but again a bit on the easy side.
Mayhem 7 - Okay,
this is the level I was talking about in the above post. This is my favorite level from this pack! Well done on this one!
Mayhem 8 - This one was annoying...
Mayhem 9 - But this one was pretty good.
Mayhem 10 - This one was also quite good. Although, you may want to adjust the placement of the water - if a lemming tries to climb up the steel block in the bottom-right, it drowns. (Doesn't happen to lemmings merely turning around at it; they have to try to *climb* it)
Mayhem 11 - Pointless at first glance, and then hidden traps in the wall... this is not a very good level, sorry to say. Though I also think that perhaps some variation on the design could make this one into a good level.
Mayhem 12 - This one was really good.
Mayhem 13 - Build, build, build, build, build, build, build... >_>
Mayhem 14 - Pretty much identical to one of the good Taxing levels, except with bomber timing instead of fairly-manageable diggers. Unlike its earlier version which was one of the best levels in the pack IMO, this level is awful. I would feel SO sorry for anyone trying to play this without Lemmix especially.
Mayhem 15 - This one was pretty good, I thought. Required a bit of clever thinking.
Mayhem 16 - Build build build build build...
Mayhem 17 - This one was fairly good. Though why the gap under the exit (though that can be said for the earlier version too of course), it doesn't really add anything to the level. Perhaps remove the trap and reduce the number of builders so the gap actually serves a purpose (to let the worker pass)?
Mayhem 18 - With this one having a creative lower half, as well as a fairly limited number of builders, this was actually a fairly good level despite being builder-heavy.
Mayhem 19 - This was very good!
Mayhem 20 - ... did you actually intend for this to simply be a matter of building onto the top of the block, or is that a backroute? (If so, I have no idea what you intended, unless it was bomb the whole way through in which case, BOMBER TIMING >_>)
Mayhem 21 - Not a bad level as such but why is the save requirement so low? My solution saved 95%, I could probably have improved that a bit further if I tried. And especially given how many builder-heavy levels you have, seeing "80 builders" in the skillset almost made me want to skip this one at first, until I noticed it didn't actually rely so heavily on them as such. (The amount of blockers and bombers is also somewhat excessive, but at least it isnt' off-putting as such.) ... I do hope you weren't intending for the player to bomb their way up to the exit from underneath it, though...
Mayhem 22 - Another EXCELLENT level, as I mentioned in the comment on its earlier version.
Mayhem 23 - Build build build build build build build! Oh my bad, need a floater first... but still.
Mayhem 24 - Build build build build build build!
Mayhem 25 - As I mentioned in the above post, this is a great level but once again, why is the requirement so low, especially considering that 100% is possible without
too much difficulty?
Mayhem 26 - Left half: BUILD BUILD BUILD BUILD BUILD! Right half: Far too easy for Mayhem. Trapping the crowd involved an interesting trick, though.
Mayhem 27 - Now this was another EXCELLENT level.
Mayhem 28 - This one wasn't too bad either.
Mayhem 29 - This is a decent level, though a bit on the easy side.
Mayhem 30 - I think my solution might be a backroute, but if not, this is FAR too easy for Mayhem at all, let alone the final level of it.
So in short - there are some absolutely
excellent levels in here, but some feel like you've either designed something and not wanted to improve/discard it, or that you ran out of ideas and had spaces to fill. You definitely have potential as a level designer; indeed my earliest levels were a lot like this pack, whereas the ones I make these days (as far as I can tell) are thought of quite highly - so I am DEFINITELY not saying give up on making levels.
By the way, I attached my replays for Mayhem.