Alien Front Online (Sega Dreamcast)

The Triclops have invaded the Earth with a simple plan: the eradication of all human life! Become a tank commander and obliterate the alien invaders, or join the elite Triclops Guard and crush any human scum that stand in the way. Regardless of which side you choose, you'll possess enough weaponry to completely destroy your enemies. One team will decide the fate of the globe!