Universal Century Gundam Online

Universal Century.net Gundam Online was a massively multiplayer online role playing game (MMORPG) based on the "Mobile Suit Gundam" anime series and set during the One Year War timeline of the Universal Century era. In the game, which was only released in Japan, players created their own characters aligning with either the Earth Federation of the Principality of Zeon. Players could pilot mobile suits and vehicles, craft items and explore the game world.
The game took place entirely in a stylized version of Australia, though a later update did add space (but not colonies). The entire game was open player-versus-player, meaning that a player could be attacked by another player at any time, anywhere. Also, upon destruction the player's mobile suit or vehicle that they were operating were permanently lost, as well as anything equipped onto their mobile suit or vehicle and, sometimes, items from their cargo hold.
Many mobile suits made an appearance in the game including the GM, GM Cannon, Guntank, Guncannon II, Acguy, Juagg, Zogok, Gigan, Agguguy, Full Armor Gundam, Zaku II, Zaku Cannon, Dom and many, many more.
The game was released in 2004 and shut down in December of 2007.