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
You are engaged in a great robot firefight. Shoot down the attacking robots with different weapons. Walk with the WASD, shoot and aim with the mouse, change weapons with the numbers, use C to crouch and F to pick up stuff.