That IGN review is pretty much... Eh bad all round. I agree it's aged badly but if they are going to be harsh with graphics for a game like Sonic Adventure, I hope they take other games at the time to the cleaners too. Furthermore even with the bad voice acting, that game still has a good enough soundtrack.
But then you read the review, 2D sections? Hard to find action stages? Characters only walk and not run in the Adventure Stage? The controls are different over the action and adventure stages?
Liars, truly, there is nothing else I can say, the majority of that review is a lie. Heck they mention the different abilities certain characters have, but not even mention how drastic each one's objective is. All starting off with the same "I was a SEGA kid blah blah" this really is one of the worst reviews I've read...