Very nice!
I like the implementation of theme and limitation. It is fun to play. At first though I didn't know what to do. Maybe in-game tutorial for buttons would be fine here. or at least when there is something interactable near; highlight it and show hint like "press E to interact" etc. But I did figure it out eventually and you have some instructions in the page as well so no biggie.
Oh and the game doesn't pause when you open the menu or any interactable view on screen, which is a bit bummer.
what you do when you run out of bullets? Oh you can buy guns.
Getting shot changes camera angle which kinda bad. like if you try to pick up gun from ground and camera reset to horizontal. Also its very hectic when you are being shot while in some UI. closing UI doesn't happen from ESC what I would think, but from the same E key. E key is fine but more options would make it better.
Anyway good job! You got really much done in so short time!