This game looks beautiful and it cant be emphazised enough, the concept of killing an enemy and take their weapon is one i like because i did one similar, but what i find it detrimental is that there is no weapon laying around and killing multiple enemies only reward one weapon, that makes it a bit unfair because some of the time projectiles go through the enemies.
The camera is bonkers, it tends to zoom or spin like crazy its really hard to dodge when your screen is going nuts, please fix this as soon as possible.
Summary, gorgeous game that is unfair with a broken camera, try teamming up with a good Game Designer or Programmer next time and your game will be perfect.