Building on the storyline introduced in The Shadowlands, Alien Invasion expansion pack was the next REPLACE to the Anarchy Online game. This expansion introduced player-built cities, player-owned shops, new social interactions and clothing, and, most significantly, a new threat to the world of Rubi-Ka in the form of an alien race that has suffered tremendous pain and death because of human interference in the Shadowlands. It was released in September 2004. try to find solution for mechs and aliens problem in FAQs section on official site of the game.