Neat little metroidvania.
Excellent art and aesthetics. Gives me vibes like its set deep underground. Animations are nice too. Very impressive how much you've managed to make in the Jam timeframe.
For improvements, I think the controls need reworking, i.e. adding mouse support for the attacks (J -> Left Mouse, K -> Right Mouse).
Overall, very pretty game that needs some work on the combat/controls. Well done. Definitely would recommend spending more time developing it.