Shadow the Hedgehog[a] is a 2005 platform game developed by Sega Studios USA, the former United States division of Sonic Team, and published by Sega. The game follows Shadow the Hedgehog, a creation of Doctor Eggman's grandfather, Prof. Gerald Robotnik, as he attempts to learn about his past while suffering from amnesia. Shadow the Hedgehog introduces third-person shooter elements and nonlinear gameplay to the Sonic franchise. To defeat enemies, Shadow can use various weapons and special attacks, and most levels have three possible missions that the player may choose to complete. The missions completed determine the game's plot and subsequently playable levels.
The development team wanted to make a game featuring Shadow to capitalize on the character's popularity and resolve plot mysteries that began with his introduction in Sonic Adventure 2. It was written and directed by Takashi Iizuka, produced by Yuji Naka, and scored by Jun Senoue. Iizuka, who targeted a younger audience with previous Sonic games, strove to attract an older audience with Shadow the Hedgehog; Shadow's character also allowed the team to use elements otherwise inappropriate for the series.
The game was revealed at the March 2005 Walk of Game event, and it was released for the GameCube, PlayStation 2, and Xbox in North America and in Europe in November 2005 and in Japan the following month. Receiving generally unfavorable reviews from critics, it was criticized its controls, mature themes, level design, and addition of guns and other weapons to traditional Sonic gameplay. However, some praised its replay value. Despite this, the game was commercially successful, selling 2.06 million copies by March 2007.
It is the first game in the series to utilize the voice actors from the 4Kids dub of Sonic X. It is also the first Sonic game to receive a E10+ rating from the ESRB, due to its mild use of profanity and fantasy action violence
Shadow suffers from amnesia at the beginning of the game; Other than the events since Sonic Heroes that took place prior, Shadow remembers only two things: his name and his attempt to escape the Space Colony ARK with his creator's granddaughter Maria, who was killed by G.U.N. soldiers.[17] Having walked through a room filled with androids that look like him during the events of Sonic Heroes, Shadow wonders if he, too, is an android.[15] The game starts with Shadow reminiscing outside the city of Westopolis when the alien race Black Arms drops out of the sky and invades the city. Black Doom, the Black Arms' leader, contacts Shadow and tells Shadow of an old agreement Shadow made to bring the Chaos Emeralds to him.[18] Stunned that Black Doom knows his name, Shadow searches for the Chaos Emeralds to learn about his past.[19]
The game progresses through the Westopolis level and five more levels from the different paths Shadow may take. As missions are completed, Shadow learns more about his past and regains memories.[4][15] He can choose to help Doctor Eggman or the Black Arms, to help G.U.N. and the series' heroic characters, or to help neither and keep the Chaos Emeralds for himself.[13] The missions completed determine which one of ten possible endings will be seen after Shadow collects all the Chaos Emeralds and defeats one of the game's final bosses.[20] The possible ending events range from planning to defeat the Black Arms to planning to destroy the planet.[21][22]