Interesting game!
I very much enjoy the idea of the gameplay though I think it could benefit from some extra mechanics long term such as having/being able to put up obstacles to control the flow of the enemies a bit more to make it easier to hit them!
UI Information
It can however be fairly hard to tell whats going on at times (using T to open the vehicle details helps a lot with this)
It can also be hard to keep track of when you can press M to progress as the zombies still keep spawning making it hard to look sometimes
Explosives & Key bindings:
It also took me a good while to figure out how to use the explosives, which I promptly noticed were very hard to aim
this is in part due to how it also (sometimes?) alternates which arm it's shot from
( I think listing the keybindings for shooting on the game page would help with this! )
Menus:
In the menus i've noticed that if you hold a button it seems to get repeated
This is good when you want to adjust the volume/buy a bunch of items but problematic when you want to do things like start a mission as it's very easy to just accidentally trigger things in the sub menu if you hold the key too long
Turning:
This has been brought up before but the turn mechanics sometimes get stuck and feels a bit slow/hard to aim with at times and I think the game would be a lot more fun it this was a bit easier