Merge Round Racers is a car-merging game. If 'merge games' is a new genre to you, the idea is that you merge items together to upgrade them. In Merge Round Racers you're given a starting amount of coins from which you can buy a couple of small cars. If you place the car onto the track, they drive around and each lap earns you coins. If you get two cars of the same type, you can merge them together to upgrade the car.
Upgraded cars generate more coins per lap. The idea being that the more cars you merge, the more coins you earn, leading to new and improved models.
You can have several cars racing around the track at the same time, keeping your income constantly coming in. There are power-ups, such as turbo boosts and helicopters that cause large coin increases, which of course leads to even better cars being merged!
It's strangely addictive and fascinating to see which level you can get to. Another superb game by TinyDobbins and Poki.