The only game on the US market that is sold with a PS2 hard drive (40GB). Although more games have plans to use the hard drive (such as Resident Evil: Outbreak), there is currently (as of September 2004) no other way to get the hard drive than to buy the Playstation 2 version of Final Fantasy XI.
The first Final Fantasy game to be exclusively online. Also, coincidentally, the first massively-multiplayer online role-playing game to have a discernible beginning and ending, with a story line that every player can experience at any time.
Although wildly popular in the US (with more than 500,000 subscribers as of early 2004), the game was less so in Japan. Square-Enix made a public claim that unless they could get 200,000 Japanese players to sign up and play the game, it would not be exported to the US due to financial failure. The release of the PS2 version shot up sales enough for US players to get the game.