Mechanically, very favorite one so far! I love the conception as well as the execution. The ambience sfx in the start screen is amazing, really adds to the vibe. Voice acting is awesome, I DID NOT EXCEPT THAT!! Loved the distinct effects for each bullet. I loved that every bullet type added so much to the gameplay.
Listen, you have something really good here. I care about this game so if you are going to work on this game after the jam (I'll encourage you do), here are somethings that I'd love to see;
1. It wasn't clear when the hit landed on them. I was constantly looking up at their health bar to see if I did some damage or not.
2. I'd love to see if there was a way to learn what each bullet does in a diegetic fashion instead of going into the settings to read about them.
3. Optionally, make the bullets a tad bit easier to hit. It's very common in shooting games that use projectiles instead of hitscan to make the bullet colliders comically bigger than they are supposed to be. And it works, because it adds fun - which is it's all about.
4. Make me jump higher!!!
That being said, your game had me hooked for quite a while. Good one!