Popular games involving Sega's flagship character include "Sonic the Hedgehog," Sonic the Hedgehog 2," and "Sonic CD." Sega stopped making game consoles in 2002 but has continued producing games, including many more in the Sonic franchise.
"Sonic the Hedgehog" was the original game that launched the hit series, although many gamers thought it was so close in design to Nintendo's "Super Mario Brothers" that they questioned its originality. "Sonic the Hedgehog 2" is considered by many to be the best game in the series, as of 2015.
The "Sonic CD" game introduced a completely different world to the game's fans. It introduced Metal Sonic to a high-tech industrial game environment.