Sonic the Hedgehog (commonly referred to as Sonic '06) is a 2006 platform video game developed by Sonic Team and published by Sega. It was produced in commemoration of the Sonic series' 15th anniversary, and intended as a reboot for the seventh generation video game consoles. Players control Sonic, Shadow, and new character Silver, who battle Solaris, an ancient evil pursued by Doctor Eggman. Each playable character has his own campaign and abilities, and must complete levels, explore hub worlds and fight bosses to advance the story. In multiplayer modes, players can work cooperatively to collect Chaos Emeralds or race to the end of a level. Development began in 2004, led by Sonic co-creator Yuji Naka. Sonic Team sought to create an appealing game in the vein of superhero films like Batman Begins, hoping it would advance the series with a realistic tone and multiple gameplay styles. Problems developed after Naka resigned to form his own company, Prope, and the team split to work on the Wii game Sonic and the Secret Rings (2007). As a result, Sonic the Hedgehog was rushed so it could release in time for the holiday season. It was released for Xbox 360 in November 2006 and for PlayStation 3 the following month. Versions for Wii and Windows were canceled. Downloadable content featuring new single-player modes was released in 2007. Sonic the Hedgehog received praise in prerelease showings, as journalists believed it could return to the series' roots after years of mixed reviews. However, it was a critical failure. Reviewers criticized its loading times, camera system, story, voice acting, stability, and controls. It has been frequently described as the worst game in the series. In 2010, Sega delisted Sonic the Hedgehog from retailers, following its decision to remove all Sonic games with below-average Metacritic scores to increase the value of the brand. Its failure led to a rethinking of the series' direction; future games ignored its tone and most characters.