Sonic the Hedgehog is a 2006 platform 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.