Sonic Unleashed had a lot of potential, and some individually terrific stages, but the overall project was a bit of a letdown. SEGA wouldn't perfect the 3D Sonic gameplay -- after so many attempts -- until Sonic Generations, a game that at last seemed to get it right.
Enter the Unleashed Project -- a total conversion mod that takes Unleashed's daytime levels and tosses them into Sonic Generations -- complete with the latter game's superior controls, graphics, and framerate.
As someone who saw a lot of potential in Unleashed but was disappointed by the full experience, I love this idea. Definitely going to have to try it out as soon as I time.
Unleashed Project [official site]