This is by far and away the best game on the Sega CD. Many people say that this is the best Sonic game of them all. You could make a case for it, but in my book, the Genesis titles are better. The games levels are uniquely designed. The concept of time is very innovative (you can play the Past, Present, and Future versions of zones). However, the game is a bit too short, and the bosses are extremely easy. This game is the best Sonic game on a CD, like all the original Sonics, it puts its 3D brothers to shame. If you don't have a Sega CD, or you never played it, you should find and buy one just for this game. It is that good.