In Riding the Rapids, you get to paddle a kayak down four mountain rivers, each more hazardous than it's predecessor. The idea is to steer and paddle at the same time, avoid the side of the river and the various rocks and small islands, and on top of that you have to travel through the flags in the right way and get through the course in the fastest time possible.
Graphically the game has not much to offer. A sprinkling of dots for a rock here, another sprinkling of dots to show the bank there. Control is easy to get used to and the courses can provide a challenge in places. My main gripe though is the speed it is so slow. The old New Generation game - Shoot the Rapids was tons better.