Hey! I've played it for a dozen minutes and I have a little bit of feedback! Of course it's a jam game so my expectations are in line with what we can expect a solo dev do in such a short interval of time.
First of, congratulations for finishing the game in time! This is an accomplishment by itself! Also I found no bugs and the game plays smoothly. Finally, the hero's sprite and the enemies' sprites are charming and to my taste.
I can think of two low effort balancing tweaks which I guess could bring the game's qualities to the forefront.
First I think the game could progress faster in difficulty and offer more enemies sooner - most of my time on these initial levels was walking around, as this wasn't fun I got increasingly tempted to buy speed potions en masse just so I could get to action.
Also it would be cooler if some enemies had less hp and some more, so my weapon upgrades could be useful even if I don't focus all my points there (I spread my points around a little, not much, but I'd always end up having to strike twice to kill enemies).