Yes, there's actually a bunch of Sonic games on Steam. They're easy to miss in the piles of other action games, but 2011's Sonic Generations deserves special notice for its thriving mod community.

普段Steam版ソニックアドベンチャー2バトルでRTAを嗜んでいる者です。 めでたくも今年の1月、ついにソニアド2がSteamでおま国解除され日本でも買うことができるようになりました。 めでてえ～！！！ しかしこのソニアド2、PS3，Xbox360用に移植されたHD版を ...

Sonic Unleashed has been brought to PC thanks to intrepid modders. My first question was "why?" but now it's "how?" as the game doesn't exist on the PC format. it's simple: they modded Sonic ...