Goofs

In the lab, the test animal "Mr Stinky" is a rat the first time we see him, then a gerbil, then a dwarf hamster.

After the guy tells his friend that his uncle has been killed, there are cheerleaders behind them. But as the guy walks away in the following wide angle shot, the girls are gone.

The long barreled revolver fires 7 shots.

(at around 5 mins) In the first scene, the male "corpse" can clearly be seen breathing.

(at around 1h 15 mins) When Jeremy (Jace Manoli), the DJ, says "Brains!" and then attacks Jenny (Jenny Mollen), the glass in the window is clearly already broken before he hits it and falls through.

(at around 50 mins) When the interpol agents pull out the rocket launcher, you can see sunlight shining through it in some shots, indicating it is just a hollow tube.

When the "Rave or bust" zombie walks away, he is wearing some kind of shoes. The shape of the soles is clearly outlined as he shuffles on.

When Julian and Jenny are facing of against Jeremy, Julian is wielding a slide action pistol with the slide closed. He pulls the trigger several times with the hammer clicking each time, telling him he's used all of his ammo. When a slide action pistol runs out of ammo, the slide locks open. Beyond this, the hammer would only click once because the slide opening when a shot is fired is what cocks the hammer.

Becky, Julian, and Cody are the three main characters in the previous film. They seem to no recollection of zombies or anything that has happened. Also Julian is upset when he gets the news about his uncles death, yet he tried to kill him in the previous movie and as well the cause of his younger brother's and his parents and his friends deaths. Julian also remarks he didn't know what his uncle work on yet he told him and his friends in the previous film what he did.

(at about 38 mins) A boom mic is visible in the reflection of the roof of a car.