We realize that Splash! is not the most intuitive game, so this is an attempt at a tutorial.
Here is the game screen:You are the yellow whale at the bottom. You can move left or right using the left and right arrow keys. Since you are enviromentally-minded and conserve energy, you move slowly.
You are equipped with a anti-pollutant nano rifle. You use the mouse to change the shooting direction and the left mouse button to launch a nano in that direction.
When the nano comes in contact with different objects it generally gains points. Hitting the pollution bubbles is the main way of obtaining points. The more bubbles you hit, the more points you earn. You can also score points by hitting toxic barrels, and gain x4 multipliers by cleaning the polluted clouds.
Besides producing bubbles, the evil factories also toss toxic barrels into the ocean. If three of these barrels hit the ground, you lose. As more barrels hit the floor, the seaweed begins to die and Alfred the octopus (lower right hand corner) becomes more alarmed. You can stop the barrels by catching them with the whale. Just move the whale underneath a barrel to catch it. You can hit barrels with a nano to slow their descent.
After you have collected three barrels, your whale converts the toxic material into a windmill, which floats to the surface. Create three of these windmills to win.
Occasionally, special fish swim by. You can gain special powerups by hitting the fish with a nano.