Thanks, the game was made in 3 days for a Jam, so it's not too much code. It's made in Pico 8 and if you have the program you can find the source code here : http://www.lexaloffle.com/bbs/?tid=3467
It was worth every minute, thank you very much! I played it almost a whole day and enjoyed thinking about it, listening to impact sounds and trying to plan my way through. It would be a great mobile game, too, It's really easy to imagine it taking off just because the mechanic is so attractive.