the action felt close because of the zoom level, i think this is a lean-in or lean-out kind of choice for the game design, lean-in might mean designing more surprise/horror mechanics with enemies jumping or lurking out of darker shadows, lean-out might mean designing a zoomed out survivors/shooter style gameplay. i think adding more strategically diverse or flavored upgrade options early on would be good too, it gives more player agency and makes players want to see how their strategy works out.

EDIT: i forgot to mention the psych horror vibe was cool and i think the idea of a last ditch high risk treatment as gameplay could give a lot of room for surprising mechanics

Loved the psychological aspect of the story and the way it's presented, my feedback would be to being able to aim with the mouse, maybe make the upgrades also focus on the strength of the character (like being able to double shoot or shoot faster and do more damage, also the last upgrade saying hp +10, I had no idea how much of an impact +10 hp is would be nice if it showed a percentage increase like hp +200%, as a player I then have an easier understanding if I want to focus on upgrading it first or not). This is more of a personal choice, but I would zoom out the camera a bit, because sometimes when I see the shadows or enemy bullets they come on the screen faster than me reacting to them which leads to kinda an unfair feeling (I love the character sprite and I understand the decision to make it more zoomed in (to see the sprite better as well) as that does make each encounter with the shadows more threatening if I am not playing cautious and just running around). Either way I think you guys have something really unique going on with this one <3