Both graphics and audio are excellent.
The game is very rich of elements and does not appear to be glitched. That is great.
The sword has a very short range and combined with the health of the first boss makes the first part very long, this may discourage some players. The rest of the game was fun.
At first it can be hard to understand that some blocks can be pushed, maybe you can add something to make it more clear.
It is one of the best game I have found so far among the jam entries.