The screen is covered with colored sprites (squares or circles). When you align 3 or more in a row, all adjacents sprites of the shape & color vanish.
You can only swap adjacent sprites vertically or horizontally. You can swap sprites even if it won't result in a 3-or-more alignment, but that will cost you 10% of your current score.
The game offers two variations on the gameplay and manages a list of current games, that you can pause and recall at any time.