This is awesome! I'm hooked, lol. Reminds me of a game I played once that I can't seem to remember the name of… but it had a lot of cool puzzles like this. Speaking of that, I seem to be stuck on a box-push puzzle right now. Or two puzzles, technically. It's on "Volcano (Level: 2)". Here's a picture of it.
Anyway, onto my critiques/suggestions! The graphics are good, but at times it's a bit hard to tell things apart. It'd be nice if there was a bit more contrast, especially between the player and the background. Also, a map would be SUPER handy. I've forgotten where I've gone or where I'm going a lot while playing, so it'd be nice to have a way to keep track of that.