Enjoyed playing this game! I like the simplistic graphics and puzzles. I found myself a bit stuck on the room with the stairs but managed to get through it with a sort of glitch.
Glitch:
Not sure if you are supposed to be able to do this but you can beat the last two levels by continuously pausing and playing whilst jumping on the cube. This effectively means that you can move upwards. If this is considered a glitch, I`m not sure how easy it would be to fix it as the glitch uses one of the core mechanics of the game.