Stunt Machines Lite is a very short racing game for Mac. It is a free game which only has two playable levels.
The full version, which costs $2.99 at the Mac App Store, includes more levels and more vehicles that you can race with. The Lite version lets you race with a monster track and a street motocycle. There are two levels: Test Drive and Easy Trip. The whole goal of the game is to complete the level as quickly as possible. If your vehicle crashes, you lose, and you have to start again. There are some terrain features that make your vehicles jump like crazy. You have to balance your truck with the left and right arrow keys which let you control your car. For example, while I was racing with the monster truck, I hit a couple of bumps on the road and the truck went flying in the air doing all kinds of crazy spins. Whenever I failed to balance the truck in the air, the level was over. This is easier said than done, though.
The two levels can be completed in less than a minute, total. After that, all you can do is try to improve your times. To be honest, this game isn't really worth the hard drive space that it takes. It is short, the controls aren't good and the graphics are sub-standard.
The game is easy and quick. You won't spend a lot of time on it, as the free version is pretty small.