Chrome 42+ disables NPAPI plugins like Unity3d plugin.
Copy and paste the following text into your browser: chrome://flags/#enable-npapi and enable the NPAPI plugin.
Or try another browser like Firefox
In this fourth edition of the Pixel Warfare series you can join a room and play zombies mode. Defeat your opponents before the time runs out. Use the arrow keys to move, mouse to aim and shoot, space to jump and 1-6 for weapons.