.hack//Mobile is a cellphone game only released in Japan and not much is known about it. From the screenshots found, it seems to be a 3D game done in a first person viewpoint. It was playable online and people were able to form partys, participate in guilds, write to a BBS and exchange mails. Seems very much like a prelude to Fragment. The cellphone requirements are to have it be part of the NNT DoCoMo 505i series.
Screenshots
