Immensely fun, would go see it again.
I've been a sonic fan since Sonic 1 and 2 on the Genesis, enjoying both the comics and some TV shows as well. This FELT like sonic to me. It captured his confident attitude and gave him a backstory that was really touching and a great character motivation. Fans of the Mobius universe will recognize more references to the franchise, but this film is great for casual fans or even newbies to the franchise too.

The most jarring element for me was Jim Carrey's Robotnik. He didn't feel like any iteration of Robotnik or Eggman that I know. He was a fun character all the same but aside from his final costume he felt maybe 5-15% Robotnik throughout the movie.

The jokes were well done and there were times the wpile theater was in stitches. Lots of dad jokes, but the kind that makes you actually laugh.
Over all this is definitely a 10 for me, one I want to buy when it comes out and I am sorely hoping we get a sequel.