This is gonna be good! i want it now!

This looks pretty darn cool. What is the object of this game?

Make Blocklanders crave the terrain =P

Or just having fun and testing your skills along with sharpening new ones. (Dev)

Now make the ground completely flat.

I really want this... c:

Good job, This is a really good game. I really want it.

Using in-game signs rather than pop-up doesn't constitute "teaching by level design". Usually this teaching-by-level design stuff happens at the unconscious level. Super Mario Bros. Did and does this already. Look at Braid. It's a great platformer, teaches by level design, and use time-manipulation in clever puzzles. The action-based plat former concept has already been dominated by titles like super mario brothers and psychonaughts. You could also go for a VVVVVV approach.