Sonic Riders: Zero Gravity is a hoverboard racing video game developed by Sonic Team and published by Sega for the PlayStation 2 and Wii. It is the fifth pure racing game in the Sonic the Hedgehog series, and the second entry in the Sonic Riders trilogy, a spin-off of the main series. The game received mixed reviews from critics, who praised the graphics, track designs, music and the more simple gameplay mechanics compared to the first Riders game, although some criticized the controls, story and lack of online multiplayer. A sequel, Sonic Free Riders, was released for the Xbox 360 in 2010.