I just saw it yesterday, best video game based movie to date! Of course there are some plot holes and the plot is pretty basic but I just accepted it as another interpretation of the Sonic mythos. Jim Carrey was awesome and I liked what they did with this version of Sonic's personality, I liked how Sonic's new image felt more as a combination of his three selves over the years: the short spines and adorable look of classic, the green eyes and fit body of modern and Boom with the blue furred arms. I want to gush more but I don't want to spoil, however if I had to rank it myself I'd say it was a 7 or 8/10, enjoyable but still flawed. However I suggest to at least check it out once or wait till it comes out on streaming or on dvd.
Hope they can make a sequel someday, if they do what do you all want to see?