I don't have many pointers, A game with this good execution doesn't even feel like it was made in one month, it is simply wonderful, with nice bosses, original concept, great music and sound effects, stylish UI and the list goes on and on.
some small complaints are that some of the boss projectiles take too long to de-spawn cluttering the screen too much with no chance to escape when another attack follows up,
and some projectiles spawned too quickly (the jokers chain start) or on top of the player (like the face`s sweat on the upper side of the circle), also Imo the pips required to make a boss vulnerable increase too much by the end.
there are also a lot of small things to compliment, such as the color choices and others. I won't get into detail else I will be here for quite a while!
games great!
For sure one of the finalists!