Viral Defense

The portals are starting to appear near our underground tunnels. If the Computer Bugs make it to a tunnel entrance they will go to the cities and spread the infection. You need to command the Cyber-Goblin army in building up our defenses to keep the enemy at bay. Be carful, these digital creepy-crawlies will destroy pieces of the ground to get to their goal, however they cannot get past hard blocks. Survive for as long as you can while we evacuate and seal off the tunnel system.