Becomes tiring, and simple.
-How slow he moves really takes away from it being a puzzle game..
-You're adding too many abilities throughout the first couple of levels. Give me room to breathe.
-Fairly simple, so it's still the same puzzle gamer.
If i were you..
-Create different worlds with different abilities that you center around (Copying blocks, copying yourself, breaking blocks, etc.)
-Faster walking
-Throw in something in the background
-Want to add some history/story?
Not much wrong with it, just.. normal.
Other than that, what really separates it from other puzzles? Try to emphasize that point in the game.
Don't tell me, show me.