Sonic Eraser was a puzzle video game that was available to owners of the Sega Meganet, a modem for the Sega Mega Drive in Japan. Other than his sprite, there is little that relates the game with the rest of the Sonic franchise.
The games availability is quite rare due to its Japan-only release and the lack of success of the Sega Meganet. However, a ROM image has been made available on the internet in 2004.
In the versus mode, when a player gets a combination of three consecutive lineups of pieces, that player's Sonic attacks the other player's Sonic. The other player momentarily loses control of his pieces.
The game is on Sega's B-Club download service.
Read more about Sonic Eraser: Gameplay Modes