Really great play on the theme that is executed very well. The art is great, the music is great, and I love his little stabby animation. I think this is pretty close to being a perfect entry.
I do have a handful of small complaints, though. The collision with the boxes feels like it could be a little more generous so you don't get hung up on things nearly as much. I think you should probably move the gravestones up further, because it feels a little bit like a betrayal of the theme to have to go into the level to read them and then restart to finish the level because you've gone too far in.
Finally, I think you should have more health. Dying in one hit is a little frustrating when it means you have to redo the whole level. Also if you had a health system, that would mean that you could place health pick-ups throughout the levels in an interesting way that allows for a puzzle-y risk/reward system.
Overall excellent entry and I wouldn't be surprised to see it in the highlight video at the end.