Your goal is to drown your enemies (Sharks, Alligators, etc) by closing a round jet stream with your boat - this creates a whirlpool that will drown anyone who goes into it (be careful not to close it around yourself!).
The boat can move freely all around, controlled only by your mouse.
You must drown all of your "enemies" to move on to the next level.
At the same time, you have to avoid the obstacles floating in the river (rocks, debris, rafts, etc) and collect the bonus items:
Coins = Points
Clock = Time reduction
Stopper = Freezes your enemies and obstacles
First Aid = Adds power to your Life Bar.
The quicker you finish a level - the higher your score. you also get points for each enemy you drown and for bonus items you collect.