I really enjoyed this movie. I grew up with Sonic so even seeing a lot of the smaller references that die-hard fans can pick up was amazing. PLUS there was a lot of great modern cultural references too for the younger audience. I will say though Jim Carey did amazingly well at Dr. Robotnik, and from beginning to end on the whole movie I was laughing. The voice-over work was well, and all in all, it was a good movie.
I'd recommend seeing it.