Your mission in this awesome turret defense game is to build the defenses and stop the attackers from getting into Area 51. There is a cash bounty on the head of every attacker and each wave is tougher than the last. Use your earnings to upgrade your defences and keep the attackers at bay. This game has much more features than any other turret defense game. Not only you defend your base by building weapons and upgrading them. You can also make them stronger by purchasing modifier turrets. You can even use super damaging combo weapons by grouping together weapons and upgrading their damage to the max. Check in-game tutorial map for more information. Use YOUR MOUSE to control the game (or you can use some of many keyboard shortcuts). Have fun!