Once you started a level, you see multiple rows of bubbles with different colors. All of them are moving down in real-time. So you don't have much time to think. Now you control a colored gun, which also fires bubbles (the bubble has the color, which the gun currently has). Your mission is to combine at least 3 bubbles of the same color; if this happens, they will explode. But you can blow up 20 and more bubbles at once, just fire at the bunch of them. If there are any bubbles beneath the one that explode, and if there is no further connection, these bubbles will fall down, making more space (and providing bonus points).
If you are too slow, and the bubbles touching the water at the bottom of the screen, you loose. But if you are fast enough, and scoring a certain amount of points (you can see how good you are on your water-meter), you proceed to the next level.
The more levels you play, the more different colors you face. And, of course, the faster the bubbles will come down.
To make the game more fun, the game offers 8 different power ups. But you can't find them, you will shoot them, like normal bubbles. And when you blow them up (by combining them with other bubbles of the same color), the power up gets activated.
The game offers the following power ups: Dual Color (acting as two different colored bubbles in one; i.e. firing blue/red bubble will react with blue and red bubbles), Double Bonus / Triple Bonus (multiplying your score for bubbles you blow up), Layer Up (give you more air to breath by moving the bubbles some rows up), Prompt (will show you the exact destination where your fired bubble will attach), Freeze (will freeze the entire playfield for some seconds; you can blow up bubbles, but they do not move), Bomb (will blow up all adjacent bubbles, even if they are the wrong color), and Repaint (will color black bubbles with colors from the current level).