Things to look out for:
health/ammo packs.
The shop and perks.
Weapon ammo. All should start with %150 normal of mag and reserve. Maxammo perk, %200. Note that buying the maxammo perk doesnt automatically fill your weapons. That way you dont pay extra for something you might not need.
sentrygun and all placed items in general.
Zombie behavior. Zombies behave like zombies. They do not just automatically spawn and go after you from the other side of the map. They are not alert when they spawn and will search the map. They will watch and listen for weapon fire. The more you fire the more alert they become. They will also follow other zombies that are alerted. If you can dodge them long enough without being seen, and not firing your weapon, they will lose track of you.
As always, lag. Important to know under what circumstances it happens and what is going on at the time. Knowing that will help pinpoint the problem.
The meatgrinder: Individual zombies have a stuck tolerance during the game. Also, if this happens they dont suicide and increase the kill count. They will respawn. The normal meatgrinder is still there as the fallback in case zombies cant be reached but arent actually stuck.
known issues:
Wrong models for a couple weapons. Let me know which ones if you see.
Some animations not working properly yet. Dogs dont always jump so watch out for them at your feet.
Zombies running through walls. Its mostly how waypoints are laid out on certain maps with close waypoints in between walls. I know the problem and the fix will depend on whether or not it hurts efficiency.
On some maps the minimap, even tho there is no actual ground image, has an extremely short distance. Air support locator wont target properly since zombies are out of range.
some keybinds are using placeholders.
Projectile weapons sometimes pass through the large bald zombie on the upper torso. Not sure why yet.
Specials dont yet work.