Really entertaining multiplayer sidescrolling gun blasting mayhem! Except that there is no one playing it. If you can get your friends to play it with you, it's a blast. Does have a bot support too, but beating bots gets really boring, really quick.
You choose a main weapon, secondary weapon and a grenade you start with. Then you rampage across the map, blasting your guns, throwing grenades, collecting power-ups and defeating the lower beings. The screenshots pretty much tell the idea. Different maps and different guns call for different play styles. Use of jumps and the limited time of jetpacks can make you a very hard to hit target and a fast predator, or you stand your ground and give all you've got with your minigun that doesn't work in the air.