The main issues I had were total overkill of the screen-shake when using grenade launchers, and the feel that pellets disappear outside the screen most of the time. Also it's hard to know what gun you have without shooting it first - I think replacing the "new gun" with "<name of the gun>" would make it feel better. Also with certain guns it feels like your movement direction/speed influences bullet's speed - shooting straight when walking backwards have noticeably slower bullets.
Visuals and sound is pretty well done and does the job for setting the right "vibes" for the game. Overall I've had fun playing it - thanks for making this game!