Playing the actual game now, and I have to agree with all the reviews. As a multi-player game, it's a lot of fun. The single player mode, however is horrible. Also the controls need an update pronto, the cars move and turn like shit. It's not bad enough to take away from the game, but just bad enough to wonder why it wasn't fixed before release. Just like with the demo, the 1 player mode is mostly throw away, the story is alright, as short as it is, but the game isn't fun. The computer is cheap as hell and it takes away from the fun. Now I like hard games, Demon Souls is one of my favorite games of the last 5 years, but the computer here isn't hard, just cheap and annoying. The opponents never hurt one another, just you, and spam the freeze attack and seem to have unlimited specials.
Online, or split screen, is where the game shines and is a lot of fun. Large, destructible environments with plenty to find and explore. Plus the different modes add enough variety to the standard car death match to keep it fun.