The game looks really nice, the idea is clever and original. This is one of the slower platformers I've ever played! I really appreciate that you didn't put in any moving/chasing enemies, that would've been frustrating I think :) Jumping 2/3 squares further was a bit tricky but very rewarding when I got the hang of it. Jumping in a curve was also rewarding to figure out!
I think the flags/checkpoints should've been closer before and after tricky jumps, so we wouldn't have to walk the same path over and over again if the tricky jump failed.