Sonic 3: Angel Island Revisited

Sonic 3: Angel Island Revisited (Sonic 3 A.I.R.) is an unofficial port of Sonic 3 & Knuckles for Windows PCs.
It very closely resembles the original game, but adds features you would only expect from a modern fan game engine – including full support for 16:9 widescreen display, alpha transparency effects, and smooth 360° rotation.