It crashed on Level 10! (when I got the gem).
Lovely game, great level design. Only complaints are that on level 7 it took me 5 minutes to realise one of the blocks is actually a crate (I mean come on - how the hell am I supposed to tell?) and the speed the character walks is reeeeeaaaalllly slow.
5/5 anyway because you could fix those sort things easily if you were arsed.