Okay this is seriously underrated. I loved the Hotline Miami vibes that the mechanics were giving off, and the simple but addictive nature of adding more and more upgrades to the character was really enthralling. My only issues come from the camera and from the abilities.
The camera should definitely be headed towards the mouse instead of lagging behind the player, the way it is now its far too easy to accidentally rush into a group of enemies that see you before you see them. This game is great at giving you a feeling of being able to be tactical, take out your targets carefully, and be somewhat prepared, but the camera doesn't let you survey the battle before charging in which ruins that planning stage.
The second is the abilities. The abilities stay on even after death, which I think could be a cool mechanic (or a cool bug?) but some of the upgrades I didn't want anymore, so I went back to the lobby hoping to clear them but to no avail. For instance I got the shorter range, more damage upgrade twice which made my pistol basically a knife, which was cool...but I wanted to revert that after I realized how volatile that strategy was against the boss. But I was stuck with the ability until I completely shut down the game.
Maybe add some sort of station in the lobby to both clear abilities and top up health? That was the other problem. I got so many extra hearts, but when you respawn you respawn with the ABILITY to get that health back but not the actual health, which I wish it did. It would add to this "stronger every loop" feel that this game had to it.
The difficulty was perfect for a jam game, and I loved that every loop was a little bit different, whether that be the floor tiles, enemy placements, etc. and I appreciated that the boss was in the same place every loop so I could plan for that.
Loved the menu too, I'm a sucker for diagetic UI design, and the lobby is a perfect example of a tutorial and a respite all in one.
Overall, I loved this thing, and the amount of words I have to say about it tells you how much time I spent on it, and how much I loved the implementation. Good stuff.