The Virus 3 is a topdown zombie survival shooter. You have the possibility to kill the zombies on 10(+2) maps with 15 weapons and 3 sorts of grenades. You can compete with people from around the world in the online highscore. Overall there are 9 different modes, which you can play all with a second player.
For the people, who want the forerunner:
Account on yoyogames
But the other parts aren't as good as The Virus 3. The Virus has no story. It was my first TDS, based on Gamemaker. The Virus 3 starts exactly after the end of The Virus 2. So to speak, The Virus 2 is the beginning of the The Virus series.
If you are a german player and want the german version, you also can it download here.