pretty solid base, i think the player should start out with a more simple one shot slower fire rate and work up to the speed he currently with each progressive fight, its pretty intense out the gate. in a game like this the first boss is basically a tutorial on how to play so i think it should be even slower and have less health, the overall game package could be improved drastically by adding simple intro cinematics to the bosses, like literally if they just lerped in while player input is overidden that would be enough to give players some time to digest what is about to come. good work