Worthy addition to the classic Sonic games.
Pros: The gameplay is very similar to the original games. The game seems to be mainly based off the first Sonic game when we first met the little, although potentially deadly, blue hedgehog. On top of having your old classical enemies and settings (not to mention Sonic is one manning - um - hedgehoging it again!) you're boss battles have new twists. You have some of your old contraptions that Dr. Robotnik used against you before, but at the same time they will hold an extra surprise for you. And to add to the fun you find that the chaos emeralds are again in this game so you can turn into super sonic and blast right through the time trials with a high score.
Cons: Although Sega said they were making it so you didn't have to use the air dash attack if you didn't want to, people who attempt to do such will find that they might be put into a couple of irritating situations if they try to old school it. You will find some higher areas inaccessable unless you whack the blue floating robots with it or find all your rings flying about you if you don't reflexibly hit them while flying through the air off of a bounce pad. In this game if you jump on them you aren't curled up into your little deadly ball but just simply flying with your body straight up. You also find that Sonic doesn't accelerate as fast and slowed down a little bit from previous games. The game was also too short. Even though Sonic 4 is broken up in episodes, this one just left you wanting more and wondering why you had to blast through it so fast. Hopefully they will at least fix the speed and game length for the next episodes.
The pros I listed as well as many others I didn't far outweigh the cons, however. This game is just plain fun and should be added to any Sonic the Hedgehog fan's collection. It just leaves me looking forward to what they do with the next episodes.