You have different kind of pickups, that are dropped when monster dies.
- Heart -> heals you
- Green arrows -> 2 x speed rate for 5sec
- Red arrows -> 2x damages for 5sec
- Bombs -> blow when hit, damaging nearby enemies
You can collect those bonuses when you fire at them. Downside is: if you shoot a lot, you can sometime collect the pickup without really wanting it.
Concerning the fact that you can miss enemies when they are really close to you, I think it's a collider problem, that someone just pointed out. I'll check this after the jam.
Thanks for playing and for your feedback