Very well designed, and genuinely managed to stump me more than once.
One thing that kinda irks me though is that when you die it undoes your previous "delete/fold", even if that wasn't what killed you (i.e. you missed a jump and you have to do the previous fold/delete again"
And at risk of being banned for advertising, anyone who liked this might want to try a similar game called "Faultline"
P.S. Is the music available for download anywhere? it's very beautiful :)