I'm with Dullstar on this one; levels that rely solely on an obscure trick to be solvable are hit or miss, i.e. either the player has the knowledge about this trick being possible, then it's easy, or they don't know this can be done at all, and therefore don't even consider it. That's a recipe for dividing the audience into professionals, who already know all the tricks, and noobs who don't have a chance, due to not being able to even consider these approaches - without any "intermediates" in between.
As someone who is firmly in the "intermediate" category, I rather resent the implication that I don't exist!
All tricks are possible to discover, in theory, because Lemmings has a finite space of possibilities you can attempt on a given level -- albeit the possibility space is, in a sense, much larger than in a game like DROD or Repton, because you can assign skills on any pixel of a lemming's journey. (But when thinking about possible solutions, we don't consider every individual pixel, but rather, make broader decisions on where it does and doesn't make sense to place certain skills, even if some of the windows we consider are rather precise.)
I'm going to link here
a post from the DROD forums that describes very succinctly the "cycle" of solving a puzzle, which applies equally well to both games. (The following post, much more detailed, is worth reading as well.)
In a good puzzle, at some point in solving that puzzle you are going to get stuck, and have to look carefully over the space of possibilities, and in particular the assumptions you have probably fallen into, to see what can be adjusted. I'll give an example from a Lemmings/Lix level -- obviously this will necessarily involve spoilers. (It does, however, involve a blocker trick that hasn't been mentioned yet, so it's also relevant to this topic!)
The trick: you need to block on a thin platform to hold the crowd. You can't release them by exploding the blocker, because the platform is thin. But you can release them by exploding a faller just above the blocker, and since this also releases the blocker, it saves the same number of lemmings.
This puzzle is hard because you quickly see the thin platform and make the assumption that you can't explode there. Once you've made that assumption, you stop "seeing" that as part of the possibility space -- until you make the decision to go back and carefully examine your assumptions.
There are some levels, such as
Lemmings' Ark, where thinking about a seemingly impossible situation doesn't really lead to a specific "trick", but something more along the lines of "okay, I need to put this skill
here and this one
here..." But I clearly remember, both from playing the original game and from playing custom levels, that cases where this process of getting stuck and then having to come up with a new insight
did lead to the discovery of a new trick (as on
Compression Method 1,
No added colours or lemmings,
Attack of the Subconscious,
Don't catch me if you can) were the most satisfying and enjoyable moments of the game. That's why I strongly object to the idea of taking those moments of discovery away from future new players.
This level [I have a cunning plan] can teach you either the three-builder wall, or the fact that blockers can be freed by miners, even though the latter is not supposed to be taught until "No added colors or Lemmings".
As a side note: This level can be done without either trick
The solution I originally used was simply to use some builders as delays so that one lemming could be far enough ahead to bash through the pillar.