Fair and decent remake of the original amazing 2D Sonic games despite some flaws.
Advantages:
1) Old and new enemies, nice graphics, cool stages with innovative elements (torch, minecart etc.)
2) The game is really loyal to the original 2D Sonic games
3) Fun gameplay
4) Incredible final fight with Robotnik. Totally challenging and difficult even though it took me less than 10 lives to beat him.
Disadvantages:
1) Dull, uninspired music (did these people actually get paid for that kind of music?)
2) Excessive use of the homing attack. Yes the homing attack in 2D Sonic is innovative and makes the game really fast, but it also makes it much easier and predictable.
3) Physics: why did they have to make Sonic so slow to accelerate? He feels like he has a chainball tied on his feet when standing and trying to get a running pace.
I really hope that SEGA will bring back Knuckles and Tails as playable characters alongside Sonic for the 2nd episode. Morevoer, I think that SEGA should just make a big Sonic 4 Episode II so that they won't have to make a third one. The game needs to be launched just like NSMB Wii as a single, full game. 2D Sonic is too good for WiiWare and stuff like that.