The year is 3000 and you are network security engineer. You must use your virtual arsenal to prevent the waves of viruses from destroying the server’s firewall. Sadly your department’s budget was recently cut, so your income must come from bounties collected on the viruses. The viruses themselves come in a variety of types, colors and sizes. The larger and more advanced types are harder to kill but provide a larger bounty. The viruses have recently begun attacking in waves every twenty seconds. It seems that there is some kind of super virus controlling them. Your defense consisted of a variety of stationary emplacements along the network path. By strategically choosing, placing and upgrading towers you just might be able to destroy the viruses before they reach the firewall.