Here is a ModNation Racers review by NotReallyMe.
"This Isn't Mario kart. It's better!"
Remember five or so years ago. When Mario Kart was the only decent kart racer available and no other kart racer was worth playing. Well, that's all changed now, thanks to United Front Games attempt at the next Play, Create, Share game.
Gameplay - 10/10
The gameplay is pretty much perfect! The driving feels right and doesn't feel too loose or stiff, it finds that spot in the middle that just screams 'PERFECT!'. Unlike most racing games, you can set a speed class for your race which means whether you want a super fast race or a slow cruise you can change the settings right before the race. The Computer controlled opponents can get annoying due to the fact that they always seem to be right on your trail, but anyone with enough skill can still win if they have patience.
Customization - 10/10
You can pretty much create anything you want. I've managed to create Naruto, Gordon Freeman and Mucking Howe (A random eye with a beard and top hat that a friend of mine came up with during a boring science class), A seaside city and the Capitol Wasteland from Fallout 3. If you can dream it, you can create it.
Controls - 9/10
The controls are just like any other racing game this generation. R2 is accelerate, L2 is reverse, X is drift/handbrake. The only annoyance is that you can't customize the controls, but it's a very minor problem.
Graphics - 8/10
The graphics look great and the cartoon style suits the game very well. The characters have a nice vinyl look to them and the cars look strangely realistic for a kart racer. There are some annoyances and glitches but they are very rare and hard to notice when you're speeding down the track in your miniature dream car.
Sound - 9/10
The sound is great. An engine sounds like an engine and an explosion sounds like an explosion. The music is just like LittleBigPlanet's music, it's very child friendly but somehow entertaining to an older audience as well.
Story - 6/10
The story is you usual cookie cutter story you find in a racing game. You find out about a contest, find an old man to be your pit crew and then you try to achieve you dream of being a champion. What really makes the story unique is the two commentators, Biff and Gary. They add a lot of humor to the game and make yo want to play until the end, just to see what they say next.
Online - 7/10
The online is a mixed bag. You can usually find a good game, but some games and the ModSpot can get so much lag that you would think the game has frozen. I'm not sure if it is just me or if it's the servers so I can't really say too much about the online modes.
Overall, the game is a great kart racer that will last you a long time no matter how old you are. If your one of those people who think this game is too 'kiddy' for them, then your missing out on a great game! Remember, It isn't Mario Kart, it's better! 9/10