Just for kids
In essence, Cars is basically a racing game, not a sim of course, but it is a racing game that will put Lightning McQueen racing over and over again with some colleagues from Radiator Springs and some international visitors (a Ferrari is included).
The races are OK but they are extremely easy to any experienced player. However, as I imagine the game producers were thinking on making a game for kids, the difficult level is just fine.
The races got really repetitive at some point making it a little bit annoying.
The graphs are OK but the game has some incredible frame rate problems, every time the music of the game changes the game locks for a couple of seconds. Some boxes and other environmental things are just sucked by the ground in front of you; sometimes even your car gets half sucked by a wall or a fence.
The powersliding and tilt functionalities are not well built and not really useful. The sixaxis functionality is also marginal.
Notwithstanding, the game is for kids and kids do not pay attention to technicality issues and they will like it. The voices are good (although lightning McQueen is not Owen Wilson), the accent of the international cars are really nice (especially the Italian accent of the Ferrari and the German character). All cars from Radiator Springs are here except for the lovely Porsche 911 (Sally), I guess game producer could not get Porsche's license but this is a let down anyway, my daughter is a big Sally fan and she was really disappointed with "her" absence. In order to compensate, the game producers inserted a British "girl car" (a Mini).
In summary, the game is not worth be bought by anyone older than 10 but the ones that fit this category will probably like it. It is worth $50? I do not know, but it is definitely a fun game for kids.