Well there you have me. The levels use a lot of controlled-randomness in the generation. If I had time for it I would have thought about making a proper level editor but you know how it is for jams. If I have time available before the new deadline, I may tweak the algorithm a bit to make the bones generate further from the entrance (too easy) or the exit (too hard).
ALMOST forgot to say: Thank you, thank you, thank you! I'm happy you liked the game!