You are an elite warrior fighting an alien force in vehicle and foot based combat across a wildly imaginative and unearthly environment - an ancient alien artifact known as Halo. This giant living ring you now find yourself on is populated with strange creatures, exotic vegetation, twisting underground lairs, huge mountain chains, and countless angry aliens bent on your destruction. Snipe alien infantry, pilot vehicles, destroy installations and rescue your comrades as you strengthen your arsenal with superior alien weapons and vehicles and fight to uncover Halo’s secrets and save the human race.