The way the characters walk feels janky and the way they move in battle can also be a bit unnatural and not very fluid. For instance, in the first fight sequence, the guy does a backflip, and while in the air, pulls himself back with the power of his mind, and then does a wiggly jump off the ground. That move felt very weird. Then, when he's in the armory, he takes a silenced pistol even though he's not being very discreet instead of grabbing one of the automatic rifles right behind him. Also there was one zombie who got hit with a whack on the head (which is not enough for a zombie) and didn't explode, even though we later see that all zombies explode. I guess those were specially augmented zombies or something. Speaking of which, why would you keep deadly zombies in your lab blocking your exit at all times? And then why would you have the release mechanism be a single button? That's carnage just waiting to happen. The long fighting part felt drawn out and out of place. Right before that, a guy got rammed by a car and wasn't completely smashed up into bits. He just got nailed to the wall without any blood.
Now, it may seem like I utterly hated your animation, but I didn't. I've seen much worse and if you take some of these tips and keep improving your animation, you could make good madness. So keep practicing, dude!