Most of the time zombies pass trough walls in ''dungeons'', and the shotgun doesn't shoot at times like it simply consumes the ammo but doesn't shoot.
Also other small bugs like the characters I play as won't respawn or when exiting the Police Station for example the camera appear in another area of the map and doesn't move to the Police Station. Some items like bullets or food lands on boulders or stuff like that and I can't have it anymore. And the car got stuck in the terrain until I reloaded the game and sometimes drives buggy or clips trough the terrain.
As a suggestion if possible, to make the items like bones or bullets visible when they are hidden behind houses, fences.
Other than that, I really love the game and I found myself playing for hours the moment I installed it. Keep going, you got something great here!