There is a new build of the game on the page so I'd be curious if it addresses some of your biggest concerns from the jam. As far as your initial feedback, I've balanced weapons a bit more so you're not as strongly punished for the bigger weapons and overall made each weapon a bit more practical hopefully.
As far as map layout, I've also adjusted the layout slightly so you have more room in the "alleyways" to move between the deadzones easier. I've also changed the starting room to be outside the building to reinforce the idea that the building is the safe heaven, and giving the player options on how they want to navigate the map and which paths they want opened. I've also added the mystery box, med kits, and stronger one-shot weapons to be outside of the building to give the player a reason to leave the building.