GridBike has a simple aim: rescue all the men on each level without hitting an obstacle or crossing your own trail. For extra points you can collect coins and jewels. You only get a single life, so once you crash that's it! But don't worry: once you've reached a level you can restart from there whenever you want.
After every fourth level you get the chance to play a bonus level. In these levels you must steer through a maze to rescue the bonus man. If you succeed you get the bonus points you've accumulated, but if you crash you get nothing.
On each successive level you get an additional man to rescue, and more obstacles to avoid. The early levels are quite easy, but it quickly gets harder. All levels in GridBike are randomly generated, so you can play it over and over again for a new challenge.