Zombies are invading and there is only one place left where you can defense. You should collect power-ups and you should defense your base against the zombies as hard as possible. The invasion hardness level will increase on each time you destroy a wave. Use your power-ups when the wave hardness increases.
Game controls:
Player 1:
Move: "W,A,S,D"
Base in/out: "F"
Player 2:
Move: "ARROW KEYS"
Base in/out: "L"
Good luck!