This game has incredibly fun movement, great feeling weapons, and a really cool aesthetic.
I like the main idea of having to flash the enemies, and then shooting the weak points, it is really fun.
Also the inclusion of the upgrade system is very cool.
However, I have a big issue with the visibility, it is very dark and enemies are incredibly quick, resulting in me getting hit out of nowhere a lot, without a chance to react in time. And combined with the low health this can be very frustrating. The darkness that comes when ringing the bell would probably work if the game was slower paced, but with the speed you are going for it just makes it more unfair.
I probably haven't seen all upgrades, so if there is one that helps with visibility than I haven't gotten it.