to any of those who are struggling with lvl 15, there is a small safe spot up on the right hand wall, in between the first and second sawblades on that side. So you don't kill your nerves.
I have a really big problem with this game. I don't know about anybody else, but I invested heavily on gunners, and on day 23, my gunners stopped killing enemies, but kicked back in after a while. On day 25 they stopped, but didn't come back on, and I lost. If you can, I would appreciate it if you could solve this problem. If anybody else had this issue, please rate this up.