At its core,
Cars: Mater-National Championship revolves around one mode of play, Story Mode. Here you will lead Lightning McQueen through three areas, picking up lightning bolts (worth points that can be traded in for bonus features), paint jobs, tires, and other parts for your car, while progressing the story by competing in different events. The events in question are mostly driving-based, and consist of different types of races, from Stadium to Off Road. However, there are also a few small mini-games that stray from the norm, including Race 'n' Chase, where you basically play a game of "tag" with your opponent, and Rhythmic Rumble, a poor attempt at a music-based game and a dancing car, among others. Unfortunately, the former is quite easy to complete thanks to the ease of use of turbo, and the latter doesn't really follow the beat of the music very well.
Thankfully, the core racing modes are fun to play. They vary ever-so-slightly, including a Relay Race where you tag your partners after every lap, but all of these modes are basically lap-based and offer enough variety in tracks that keeps things interesting. There are also a few Monster Truck runs, featuring Mike and Sulley of Monsters, Inc. fame, which is a great touch. Each track will keep you on your toes, but they are also straightforward and generally have markings quite clearly on the courses. There are exceptions, of course, as a few tracks had very "hidden" corner arrows that blended into the background too easily, keeping you second-guessing which way to travel the first time around a new track. There are also a few shortcuts that can help you or hurt you, but even these are not one hundred percent necessary to take for you to win each race.
One thing to note is that on its surface, Mater-National is a bit on the easy side by default, which makes you think that you're ripping through the game quickly. However, there are enough tracks and levels of mini-games to keep you playing for quite some time. In fact, after beating the game and watching the credits roll off the screen, I was able to keep going because of a previously-missed area, and realized that you can beat the game rather quickly just following the story path, but you can easily spend twice as long to actually play through every single event.
In addition to the Story Mode, you'll have access to an Arcade Mode and Versus Mode, in which you can either race standard tracks or play through the various mini-games. As you earn points in Story Mode, you will be able to buy different items for use in the other modes, including paint jobs and other vehicles. One nice thing about Mater-National Championship is that you can customize your experience at any time, no matter which mode, by adjusting the difficulty on the fly.