Nice game, brings memories of about 25 years ago!
The game gets repetitive after a few minutes, but it's a game jam, so I can't expect much, I know. It would be nice to have to explore different areas, so you can keep the same mechanics for fighting and have a game a little bit different from what's popular nowadays.
Prerendered animations are nice, unfortunately the colour scheme you use for the spell make the enemies look like cheap variety of the same plastic toy and you can't really notice or appreciate the details. In the future you can have a predominant colour like skin, robe or armour and still have some nice details in different colours.
Initially I didn't understand how to shoot, so add an animation when you deal the hits, something that maybe start from the player or anyway makes it more obvious that you are attacking.
As others said, the skill tree is impressive, I am sure you will have lots of nice contents to add if you will stick with the development of this game.
Well done!