You'll be quite a bit hesitant at first, as you get into the plot and realized that the animators have added quite a few new characters to the already-large selection of Sonic characters. You'll scoff at the plot, which I will not ruin, because it get VERY good by the end. Metal Sonic will emerge, the final battle begins. Let's go into detail. The music in this movie is on a teeter-totter.
Some songs are great, like the previously mentioned opening theme.
Overall, they could've spiffied up the music a bit. If you're looking for an anime with beautiful graphics, stop reading now. If you want a slapstick-comedy, which is what Sonic is very good at, continue. I'll go through them, one by one. That is the best word I can find for Tail's voice.