That's actually intentional; I went around and added invisible NPCs on each wall to block them.
In early beta testing, people were spamming overwall projectiles, like grenades, launchers, slime, etc.
It was ruining the gunplay that I wanted to emphasize.
I think I'm going to remove those NPCs now that those trouble items are either nerfed or disabled inside the base.
(For example, launchers now have a longer RoF than they normally do, and grenades have a 20 second timer)
I'm also experimenting with the idea of disabling all guns from the base, and instead, having a gun that each player can customize themselves.
This way the "OP" guns won't be an issue.
Here's a video on that project, recorded tonight:
https://www.youtube.com/watch?v=swl3opsl-lE
Interesting, the medkits should have a block on them to where if somebody is dead, they cannot get one.
I'll have to check that out for myself; thanks again, man!