The original Sonic 3 & Knuckles is not sold as a standalone ROM on Steam. Instead, the definitive modern version is included in (available on Steam). This collection features:
It's essential to note that the Sonic 3 & Knuckles Steam ROM may raise concerns regarding its legality and safety. sonic 3 knuckles steam rom
For emulation enthusiasts, the most legal way is to dump your own cartridge using a dedicated USB ROM dumper (e.g., Retrode or Sanni Cartridge Reader). The original Sonic 3 & Knuckles is not