Exterminate

The goal of the game is to survive as long as you can from the onslaught of zombies. 

How to play: WASD to move; point your mouse where you want to shoot, click LMB to fire.

Theme: Everything interacts with everything

The bullets interacts with the zombies by decreasing its health; the zombies interacts with the player by decreasing its health; and the score interacts with the zombies' spawn rate and speed.

This file is in a .zip.

(The game would not upload otherwise.)