Natural Selection 2 PC, X360 game

Whether you play as one of the elite marine Frontiersmen or the vicious alien Kharaa, you must use unique strategies and your abilities to win. Marines buy weaponry and form persistent squads to find and destroy alien hives. Aliens can choose a wall-running Skulk, pudgy Gorge, flying Lerk, murderous Fade or gigantic Onos that can devour enemies whole.

Real-time Strategy
New strategy gameplay allows players to Command from overhead. Build structures anywhere, collect resources and research upgrades. The marines can build phase gates, sentry turrets and siege cannons to assault the enemy. Aliens can build upgrade chambers, evolve special abilities, lay eggs and plant traps.

Dynamic Environments
Levels change as you play. Spreading alien infestation deforms hallways and causes space station power failure, halting all lifts. Destroying a catwalk's supports causes it to fall, revealing a new route. Use a flamethrower to clear infestation, spin webs to block a passage or weld a bulkhead shut for a last defense. Every game is different.

Unlimited Variations
Flexible game rules and scripting allow you to create your own unique scenarios like "Colonist Rescue", "Alien vs. Alien" or anything else you can dream up. Free automatic updates keep the game fresh by adding new levels and abilities.