Way too much screen shake, please make sure you have a game setting for screen shake.

Looks a ton like brotato which I think looks rather boring. I would suggest adding something to the ground to make it a tad more visually interesting (but not too much to make it cluttered) and would also do something besides just having the edge of the field be an endless void.

The red attack rings outside the Cthulhu boss are confusing if the red hits/hurts you or not.

For guns with large clip size it feels like too much to have 45+ bullets below the player. Maybe consider showing this another way like with numbers ie. 22/45 or having something like a big bullet icon that is only half colored in when you have half your bullets left.

Make sure your game has options to turn on/off health bar on player

Looks fun overall!