[Alpha] generic zombie wave survival simulator

[note: this game requires a decent device. there's plenty of things that go on, such as a max of 50 zombies and other things.] anyways, generic zombie wave survival simulator! a game about surviving against waves of zombies that often times require crowd control through the usual means, also sometimes dealing with the occasional angry evolved zombie, and also marines! inspired by L4D2 and Team Fortress 2