What's the difference between a hippo and a zippo? One is really heavy, the other is a little lighter.
Whatever you do, you must not press the red button.
Press and hold the button for a long as you can endure. You might even get on the leaderboard!
The longer you wait to reset the sign to zero, the higher your score. But don't wait too long, or someone else might reset it!
Don't hit the walls, or you'll sink!