In this update I changed so many small things that I can't remember all of them, so here's what I remember:

The settings will no longer be reset when you delete your savedata.

I made the arrow showing you where to go in 2-2 fit with the level.

I made the "triangle puzzle" in 3-1 make more sense (I promise this sentence will make sense if you play the game)

I have almost finished world 4 (not playable in the demo)

That's all I remember. Have fun!