More like a remake then a sequel, but still pretty good.
Unfortunately, this is the main problem with Ridge Racer Revolution. There's hardly anything new! Everything you've seen in the original Ridge Racer is here: the cars, the stages, the announcer's voice and even some of the songs that where in the first game have been remixed specifically for this game. This makes the whole game feel like a remake then an actual sequel.
Even though it seems that it's just a copy of the original, Ridge Racer Revolution is a pretty good game, and everything isn't like it was in the original game. There are some new songs to the soundtrack and the stages doesn't look exactly like the ones in Ridge Racer did.
If you can somehow find this game cheap and you don't have the original game, it's might be worth checking out, but it's also worth checking out if you like Ridge Racer. Just don't expect anything new, and you will get some value for your money.