I really like this game, the boss is hard but fair and there a whole lot replay value from using the shop and it risk and reward sistem.
my biggest problem is that enemy bullet does not have any indication on the radar. since the only indication of enemy shooting is just the sound effect, it became really confusing on what enemy is currently shooting and where the bullet is heading into. and the fact that the bullet can sometime come from behind the player leave me with many moment where i was just playing normally and
suddenly i was just death without having anytime to understand the situation.
another problem i see is the boss have way to many hp, maybe instead of making the boss have massive hp perhaps make them around 100 but add a invisibility frame every time the boss is hit instead. this way the boss would not be defeated easily with just rapid button press.
But other than that the whole game is enjoyable enough that i have beaten the game just using the normal weapon. if only those two problem have been fix i can see myself spending some time to beat it to do No-hit run.