Sonic Rush

Sonic Rush is a 2005 platform video game developed by Sonic Team and Dimps for the Nintendo DS as part of Sega's Sonic the Hedgehog series. It was released on November 15, 2005 in North America, November 18 in the PAL region, and November 23 in Japan. It is a 2D platform game, like earlier games in the series as well as later ones like Sonic Advance. Levels in the game are side-scrolling and displayed using both DS’s screens. However, boss battles, the main characters, and a special stage are rendered in 3D, creating a 2.5D effect. The game's storyline follows the intertwining adventures of a new character, Blaze the Cat, and the series' main character, Sonic the Hedgehog. They respectively battle Doctor Eggman and his doppelgänger Eggman Nega at certain points.

The game was announced under the working title Sonic DS at Electronic Entertainment Expo (E3) 2004, and under Sonic Rush at E3 2005. The game's 2.5D format was based on Sonic Team's idea to combine elements from 2D and 3D games in the series. Upon release, Sonic Rush was well-received by critics, with praise stemming from the game's music and similarity to older games in the series and criticism stemming from its overall quickness. A sequel, Sonic Rush Adventure, was released in 2007.