This, for me, was a very mixed bag.
The animation was overall decent, the varied styles are noticeable and the shifts in style can be a little distracting at times, but having said that, none of these styles are bad, the animators and artists working on this all had undeniable talent, so I can kinda forgive it.
As for the song itself, this is where the "mixed bag" thing comes into play. I love the Seaside Hill theme so right off the bat, the song is catchy. I also love the lyrics, I don't know if this was written by one person or if that was a collaborative effort as well, but either way the writing is really funny, really clever, and I loved it.
Where it falls short, to me, is the voice acting. I thought some of these were spot-on, such as pretty much all members of Team Sonic and Team Rose. Omega was pretty much perfect as well. Espio and Shadow were decent enough, particularly when Shadow says "Chaos control", that was pretty much spot-on.
However, I HATED Rouge's voice. It didn't sound much like her and the girl can't sing. She sounds like she was auto-tuned, and even then, her voice doesn't match the song. It's like she's singing along to a different melody. As for Charmy and Vector, I thought Charmy's voice was kinda accurate, but the actual acting was off. He's very energetic and loud, the person voicing him here was very monotone and sounded too bored. As for Vector, I thought he was okay at first, but it's like he sort of lost it as he went. and by the end it was just annoying, forced, and not even accurate.
So, in a nutshell:
The Pros - Great writing, good animation, some good voice acting
The Cons - Some really bad voice acting
I was tempted to give this a lower rating because the bad things, while small and rare, did kind of annoy me. But, like I said, these problems are small and kind of nitpicky, so I can sort of forgive them. This would be pretty much perfect if Charmy's actor had a little more energy, and if Vector and Rouge were more accurate. As it is, it was decent enough, apart from the few nitpicks I had.
Overall, I thought it was okay.