If you like Sonic and you like the 3Ds, this is a pretty great game. Seems like most of the big screen stuff transfers to the small screen very well.
If you don't care much for Sonic, but you like the 3DS (like me) this game is so-so. The 3D effect isn't really geared towards fast moving side scrollers. Looks great when Sonic's in loops or the camera is from behind in the special stages. 3D isn't meant for speed, it's more for perspective and depth.
If you like Sonic 1 or something then get ready to be really annoyed when you have to do precise jumps or you'll fall off a cliff and die. No "just hold right and jump" in this game, particularly the later levels.
If you don't like Sonic or the 3DS, what are doing? Stop wasting your time looking at this review. Go outside, get some fresh air. It's nice out.
This is one of the best sonic games i have ever played! it's even better than sonic unleashed! i love playing through emerald coast as classic sonic, it just feels right to finally be able to use the spin dash again! Good Job Sega! keep these coming!