The most major bug I noticed was a way to get out of the map, around speed cola and into the tunnel down towards PHD if you jump into the rock at the bottom right of those stairs you'll just fall through the map and be underneath the zombies.

Another game breaking bug is a super easy way to evade zombies, in spawn on the staircase going up towards the first switch facing down the stairs if you jump off the right side towards the monkey you'll land on a ledge where you can stand where zombies will try to attack you but will never be able to hit you

And now some of the more minor bugs, the spider spawn point around the knife wall buy on the bridge sometimes makes the spiders clip through the floor and get stuck. Another one is with the bats on the bridge and in the jugg room, they'll sometimes fly into the wall and attack you from outside the map with no way to kill them. If you have a boss following you and you run into the power room from speed cola side and out towards widow's the boss will get stuck on the pillar and wont be able to move/attack you until you get close.