Hey yo! First, some problems: first stage - i hit the platform so hard, the cube never land, had to alt+f4, need a time or smth! Second - in the menu i manage to let my red coub go through the ground, so alt+f4 again. Then I tried starting the game from the menu 3 times in a row, with no success (cube flies away or towards the screen, so I really lost my patience there :D
So I can only rate it as far as first level, I think it is good, but controls and the third dimension arises too many problems that are not handled well as of now.
Otherwise good theme match and screenshots seem like you really spent time designing levels, so good job :)