I can say that most of zombies games are survival games. In general, people start getting bored of this concept because there are lots of zombies games in the market now. And, they have lots of things in common. The first one and the second one might be good. Players might love this idea. However, when it n+1 games published with zombies theme, everything starts getting lame. On top1apk, there are some zombies games. I was excited to try one but not volunteer to play them all. Even when some games have their own plot, it's hard to keep players all the time when they already played a lot zombies games.