article: Sonic the Hedgehog 4
links: Sonic & Knuckles Sonic the Hedgehog 2 GameRevolution Ouya Digital Spy Sonic the Hedgehog Multiplayer video game PlayStation 3 IGN Sonic Team Sonic Adventure Sega Genesis Wii Sonic the Hedgehog (character) Windows Xbox 360 Sega Eurogamer Game Revolution Android (operating system) Metacritic Electronic Gaming Monthly Platform game Tails (Sonic) GameSpot