Really fun game, although te repeat ability is completely skippable and the magnet is only required for the last room... (Also the "hardest room" becomes pretty easy by using the green side to get some height and you can just run through the rocket rooms to get to the checkpoint)
Edit:
The 'hardest room' was probably sarcastic as you can just jump on a cube to finish it. What is more interesting is that if found a way to complete the game with just explosion and magnet...
Edit 2: Explosion is only required in one room (the room with the cracking wall)
There are only 2 places where abilities are really required (maybe three, the skip is really hard to do and requires a restart if you get it wrong, it might be possible to do a cube jump in the room before the last)
I just found a skip making it possible to finish the game with only two uses of the abilities