Sonic Rivals is a 2006 action-racing video game developed by Backbone Entertainment and Sega Studio USA, and published by Sega for the PlayStation Portable (PSP); it is a game in the Sonic the Hedgehog series, and follows the heroes needing to stop Doctor Eggman Nega from turning everyone and the world into cards.

In Challenge Mode, the player is given a goal to complete, such as hitting their opponent a certain number of times during a race or battle.

They confront Doctor Eggman, who reveals his latest device: a camera which can turn people and things into cards, having already done so to Amy.

Eggman announces his plan to conquer the world by turning everything to cards, challenging Sonic and Knuckles to stop him as he flees.

He later receives a communication from Rouge warning him she has stumbled upon a dangerous secret about Eggman, but she is turned to a card before she can continue.

The heroes rescue Tails and the real Eggman, who aid them in reaching Nega's space station to stop his plan.

Sonic Rivals was developed as a collaborative effort between Sega and Backbone Entertainment for the PlayStation Portable (PSP).

[9] The developers chose to create the game on the PSP over the Nintendo DS, due to its stronger processing power and higher graphical quality.

[10] According to producer Taylor Miller, the goal of the developers was to return to the gameplay style of the original Sega Genesis Sonic games, but with new elements such as competition.

Building alternate paths—a common feature of the original games—was cited as challenging, with the goal of allowing as many rivalry interactions as possible.

Juan Castro of IGN wrote that the game had tons of "graphical flourishes" that made it belong on the handheld,[8] a sentiment shared by Greg Mueller of GameSpot.

[5] The gameplay, however, drew mixed reactions; a common critique was the game's rubber banding mechanic making the opponent close to the player no matter how fast they were travelling.