A huge collection of classic sonic games is definately worth checking out.
The stories are all different for the games, but the jist of most of them is to clear the zones sonic is in by racing through them to get to the end. The only exceptions are Flicky and Ristar, both secret games you unlock by playing the others a lot.
The gameplay has sonic jumping, dashing, defeating enemies, and basically speeding through the stages to defeat eggman(robotnik back then) and take back the chaos emeralds. Each game has their own style of gameplay, however, and will make you think on your feet. There are a wide variety of bosses to keep sonic on his toes as well.
The way the game is put together really reflects on how well sonic did in the past, and how he's stayed famous to come back in this collection. The music is still catchy, the graphics are still classic, the "museum" of comic covers and concept art is well put together, and everything wanted in a collection is included. A few extra games might have been nicer, and it takes quite a while to unlock some of the other games, but with the sonic gems collection out, anything that wasn't in this game is completed in that one.
Overall, this is fun group of original games, and all of them are very enjoyable. I recommend this to everyone. Enjoy!