Original Lemmings also did this by requiring things like the three-builder wall or digger pits to contain the crowd, and quite suddenly so, without prior explanation.
Original Lemmings is an interesting case, as the majority of its "trick-requiring" levels actually provide enough skills for the level to be done without the trick. For the three-builder wall, I imagine you're thinking of
I have a cunning plan, and for digger pits, the 100% levels in the first half of Taxing. These don't actually require the tricks in question, and I for one played original Lemmings without ever learning these tricks. (
The ascending pillar scenario in particular had me stuck for about a year -- granted I was a kid at the time -- because I hadn't internalised that diggers are better at trapping the crowd than miners, so I was trying some weird mixture of digging and mining to get down fast enough. At least learning this technique allowed me to backroute
The Great Lemming Caper later on!)
It's a grey area as to what constitutes a "trick" and what is just a combination of skills; but I think in original Lemmings, there are only two levels that are intended to require tricks and really do require them:
Down, along, up. In that order (blocker turns builder) and
No added colours or Lemmings (releasing a blocker). As it happens, these two levels perfectly illustrate two very different kinds of trick-requiring level: In
Down, along, up, it is (in my opinion) very easy to discover the trick, but the level is still very hard because of execution. In
No added colours, execution is not hard (the second miner is a little tricky), and the main difficulty is that of staring at a puzzle that looks impossible, knowing that it
must be possible somehow but you just can't see it.
It's also a great illustration that being stuck not knowing a trick is not necessarily bad. The initial frustration feeds into the feeling of immense satisfaction when you spot the trick and solve the level. (
No added colours has been voted by this forum as the best level in the original game.) Then again, it isn't necessarily good either; if the trick is too obscure or hard to work out by experimentation -- especially if it's counter to what you would reasonably expect, like many of the glitches in the original game -- then you can come away from the level feeling it wasn't playing fair. But there's no sharp distinction between these outcomes; some levels will go one way for some players and the other way for others.
The difference between a level teaching you a trick and one simply demanding it from you is obviously the prior announcement that the trick is possible via the pre-level text.
Far from being "obvious", this is
completely wrong. Right now on the DROD forum, I'm the team leader for an ongoing project in which we're building a large levelset, one level for each element in the game, first teaching its basic behaviour, then how it combines with previously introduced elements and the tricks it can be used for. In a few cases, we've had to include text -- mainly when introducing new controls, or when certain nuances of how elements behave are too complex to expect the player to figure them out from observation. But more than 90% of the teaching in this levelset is with no text, only the room design itself.
For some illustrations of textless teaching in Lemmings, see Lovely 13 "Let's Block and Blow?" in the Lix community set. The trick: the knockback from fling exploders can release a blocker. This is taught by giving the player pretty much no opportunity to do anything except perform the trick and see the result. Another example is Lovely 11 "Beneath the Lab". The trick: builders will turn when they bump on terrain, but platformers will stop work and continue in the same direction. Here, there are two possibilities you can try, and if you try the wrong one, you might think of switching the two skills to see what happens.
Unless, of course, we as a community decide to compile a separate "trick teaching pack" to point new players to. Then our custom packs can simply demand those tricks from the player without a bad conscience.
That won't really solve your problem in the way that you want. We can't demand that new players play a trick-teaching pack before any other content. And we can't cover every trick that everyone might want to include in their packs without an absolutely huge teaching pack, which would be more than likely to put new players off altogether.
In the end, you just have to decide for yourself how to rank your levels, bearing in mind that some levels will be much easier for some players because they've seen similar levels and can spot the tricks easily. That's true for every pack
Still, I think a "compilation of tricks" pack is a decent idea and I wouldn't mind contributing, if the project gets off the ground.