Among the most peculiar trends in a nation that thrives on peculiar trends is Japan's fascination with cell phone games. The market for mobile diversions is so large that many high-profile videogame companies have established branches devoted to the production of mobile content. Sega was among the first to hop onto this bandwagon in late 2000 with a series of Java applets designed for Motorola wireless phones, including four with a Sonic theme: Sonic Logic, Sonic Head On, Sonic's Bomb Squad, and Sonic J.

   In January 2001, NTT DoCoMo introduced i-appli: a Java program designed for its i-mode service. (i-mode, which was launched in February 1999, is NTT DoCoMo's mobile internet service.) On January 26, Sonic Team kicked off the Sonic Café, a line of downloadable i-appli mini-games. The service costs 300 yen a month, and is still maintained with new titles added roughly every 3-4 weeks. Following is a list and brief synopsis of every game released as part of the service. (Like the museum, games are divided by year, or simply click on a title to jump to the desired page.)

   In 2002, Sonic Team released its first and only title for PocketPC: Puyo Puyo for PocketPC, compatible with PocketPC StrongARM and PocketPC 2002. In 2003, Sega of America introduced its own mobile game label, Sega Mobile. The Sega Mobile series includes ports of the Game Gear versions of Sonic the Hedgehog and Dr. Robotnik's Mean Bean Machine for Palm Tungsten C, Tungsten T, and Zire 71.

   When Sonic Team absorbed United Game Artists in September 2003, they took charge of Ulala no Channel J, UGA's Vodafone V-appli game service. The "Ulala no Channel J" name was dropped and the Vodafone lineup fell under the Sonic Café label. UGA's original titles from Ulala no Channel J were eventually dropped, and Sonic Team has since ported over a number of games from the Sonic Café series. The Vodafone Sonic Café service costs 315 yen a month.