Well, this is interesting. Jtanner e-mailed me and told me about "Sonic Party," which is listed as a title on the Release Dates page of "Cheat Codes Central." Keep in mind that this is still a rumor, as sites mentioned title names such as "Sonic RPG" on their release dates pages before. I should also mention that Sonic Adventure 2 and NiGHTS 2 are also on the list.

If this game is anything like Maio Party, then it could be a great fit for the Dreamcast's online capabilities!

Source: Cheat Code Central