It is your task to defend your base against attackers. They will get more health after each attack. Shoot them to get money, and use your earned cash to buy upgrades and weapons. Use YOUR MOUSE to aim and fire. Hit SPACEBAR to buy upgrades. Use "1" or "2" KEY to change weapon and "L" KEY to use lasers. There is a bug in the game so you need to hit reload button in your browser to play again after you are defeated. Or simply click here. Good luck!