The basic premise is this: In the near future, there's a massive multiplayer virtual reality game called Avalon. The game is illegal due to players going into comas, but you can earn money and fame if you play well. In the game, players can form parties or fight solo, while they go on missions against tanks and helicopters and such. The film's main character, Ash, is a highly skilled player and a former member of the notorious Team Wizard. The team disbanded when a scared member called for a Reset during a difficult mission (there seems to be severe penalty for a Reset, but at least you don't go into a coma ;P). Now Ash hears rumors of a mysterious, supposedly non-existant level in Avalon. The level is said to be impossible to beat, but the potential rewards are so great that players will risk their lives attempting the mission. Supposedly there is a "ghost girl" *cough*AURA*cough* who can lead players to this secret level.
That's about as much as I want to give away. Anyway, some of you may be familiar with Mamoru Oshii already; he directed Ghost in the Shell and Jin-Roh: The Wolf Brigade. Avalon is live action, but it feels a lot like those animes. I'm still trying to figure out the meaning of the film, and what the truth was in the story. All in all, Avalon is a cool and thought-provoking film. If you're in the mood for something a little different, watch Avalon.
And for the record, Avalon was made in 2001, while .hack came out in Japan in 2002, if I recall correctly. And both were written by Kazunori Ito. I guess he just wanted to use the concept again?
