Hi, I`ve played your game a bit and I have some suggestions:
1. I think you should highlight buffs and debuffs on the upgrade selection screen. Like +10% damage should be green and -20HP should be red. It is a fast pase game so the gamer doesn`t need to think a lot while figuring out what buffs and debuffs are.
2. I think there is a little bug when you reload a shotgun. The reload bar isn`t centered above the character.
3. Game is pretty fun and addictive but I think that screenshakes should be lowered a bit. When you hold a fire button and have a lot of bullets it becomes pretty hard to track your character.
I really like your game but I won`t be a play tester. That`s because I am developing my own one. I wish you great luck with this project.
Bye ;)