While he's a major character in the Sonic the Hedgehog franchise, he's always been a part of the team, appearing alongside Sonic in games like:
* Sonic the Hedgehog 2 (1992)
* Sonic Adventure (1998)
* Sonic Heroes (2003)
* Sonic Frontiers (2022)
* And many more!
He's also had his own playable levels in certain games and has been featured prominently in spin-offs, but never as the sole protagonist in a full game.