On chapter 2 I liked figuring out how to skip an entire section.

On chapter 3 I fell through the checkerboard immediately the first time; this seems like a bug.

On chapter 4 there are enough paths that it's possible to get slightly lost and not know which way you're supposed to follow the line.

On chapter 5 it's possible to fall onto an isolated island (the pink cube, under the lip) and get trapped forever. I would suggest making "only blue saves your position" a consistent rule rather than the current randomness. At this point I gave up and didn't want to try again from scratch.