The object of Leinen los! is to push a little wooden ship, following the race track while doing so and avoiding the buoys. This might be easy to do, except that the ships are composed of two separate parts: the motor and the rest of the ship, with the latter part tending to turn in every direction except the way you want to go, but since you must move the ship by pushing on the motor with only one finger, sometimes you can't help traveling in directions unintended.
Players take turns via a chronometer/egg timer, and the first player to reach the end of the track wins!