its the ugly red fat zombies that kill the base fast. normal zombies hit 3, fat hit 5, the de-formed hit like 12, and the ugly fat ones hit like 50 in 2 seconds.
Well now thats kind of crappy. I changed my tab for like 1 minute while fighting a skeleguard. but when i came back the skeleguard had no damage on it and i almost died. glitch maybe?
I found that if your almost out of air and are lost on which way to go, just press spacebar for the last checkpoint, also that gives full oxygen again. Helped me out abit with Chapter 3.