I have one conclusion : all of the movies with zombies are more violent at the end, and the games helped for this gore side. This video will help you to understand my theory because we can see the make-up and the special effect of different movies or games, and the first zombie looks like a goth ! After we can see how much the zombie changes, becomes faster and more violent... At the end we can see one of the most dangerous in the game Dying Light. Scary !