I've seen games similar to this (usually as a sub-game within another), but they had the blocks appearing and disappearing in a set pattern, made it a little more challenging in my opinion since you had little time to think, you had to move off your current block before it disappeared made you fall.
This however is much more like a puzzle game, since you've got to figure out where to go, rather then rely on luck, so nice idea, Leys!
I don't suffer from insanity - I enjoy every minute of it!
Current Projects: Lemmings Remake
(Untitled) Puzzle Game for the Compo