I think this is one of those games that could use a bit of text explanation.
Took me a while to figure out what is happening, so I'd like to suggest some things to speed up the process.
- Replace the hearts with arrows. Lets be honest this is just an arrow counter.
- It is nice that you made tutorial levels instead of explaining everything in a gigantic text. However since we're dealing with very esoteric boxes in the game it might be prudent to tell us a little more of what we're supposed to learn in those levels instead of just the level name. (like bombs deal damage to you)
- Also a general controls tutorial (or even just a list of buttons) would be good.
There were a couple bugs and general weirdness, but there is definitely a nice game.