I love these top down shooter games so much, and the sprite work is tasty as heck. You've done some good work when it comes to the controls and general game feel, and your music is kickin, approved by the fiance.
This isn't the most creative idea, I've seen the idea done a few times already and in other jams, even this jam. The biggest problem, for me, is I felt annoyed when leveling up, i didn't want to give up aspects of the game I was enjoying, id rather just not level up at that point, I understand the use of the theme, and its smart, but didn't feel user friendly? You could fix that by making it so you get 2 points to distribute and take one away. Gaining one and losing one doesn't feel like a "level up".