This is pretty good for a first jam good job!
I think if you work on the movement and smoothness of the game, it will make the game so much more fun!
For example, you could make the scene transitions smoother with some sort of animation.
Also, the animations of the enemies could use a unique animation when they are damaged, rather than only pushing them back.
I think you should continue working on this It has great potential!
Kudos!