Previously Lost Sonic Speed DX Mobile Game Preserved

A previously lost Sonic mobile game has been preserved, giving fans a new way to experience one of SEGA’s older Sonic Cafe releases.

Sonic Speed DX, also known in Japanese as Sonic’s Speed DX, was preserved by LNRC and Cuebus. The game was originally released for Japanese mobile phones through SEGA’s Sonic Cafe service and was later made available through the Puyo Puyo! SEGA service.

The preservation was highlighted by RockmanCosmo, who noted that the game includes both CPU opponents and local multiplayer. The multiplayer mode uses a simple but clever setup, with players turning the phone sideways so both sides can play against each other from opposite ends of the device.

Sonic Speed DX is based on the card game Speed. Players choose a character and compete by playing cards as quickly as possible, placing cards that are one number higher or lower than the cards in the center. The goal is to be the first player to use all of their cards.

In Normal mode, players can face CPU opponents, with each character requiring a different Ring fee and offering a different reward. Tails can be challenged for free, while Amy, Knuckles, Eggman, and Shadow require higher Ring fees and offer larger payouts.

Sonic Speed DX, a previously-lost Sonic keitai card minigame, was preserved by LNRC and Cuebus! In addition to CPUs, the game has local multiplayer… you just turn your phone sideways. Playing the game earns you rings, which could be spent on phone wallpapers. pic.twitter.com/gxX2k1bNts
— RockmanCosmo (@RockmanCosmo) May 18, 2026

The game also includes a VS mode for multiplayer matches, along with other features such as score tracking, tutorials, and a Present mode. Rings earned through play could be spent on mobile phone standby images, giving the game a small reward loop beyond its card battles.

The playable character lineup includes Sonic, while Amy, Dr. Eggman, Knuckles, Tails, and Shadow appear in VS mode. Character artwork is pulled from earlier Sonic titles, with the hero characters using artwork from Sonic Advance, Eggman using artwork from Sonic Adventure, and Shadow using artwork from Sonic Adventure 2.

For fans interested in trying the preserved game, RockmanCosmo noted that Keitai World Launcher is currently the most convenient method for accessing it.

Sonic Speed DX is a small release, but its preservation is another meaningful win for Sonic game history. Mobile phone games from the Sonic Cafe era are especially easy to lose due to old hardware, limited distribution, and discontinued services, making each recovered title an important piece of the franchise’s wider archive.

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