You start with the hex shaped piece at the bottom left of the screen. Change the color of the swarm by picking a new color piece. The swarm will change to that new color, and any touching pieces that were already that color become part of the swarm. Change the entire board to one color to get to the next level. Every round either a new color is added or you will have less moves to complete the level.
Scoring: Every time you change the color of the swarm you get one point for every hex piece in the swarm. If you have moves remaining after completing the level you get one point for every hex piece on the board for every move remaining.
Minimum High Score: 50,000 - required to qualify for a high score.
Strategy: Don't worry about the one hex piece that is already surrounded by the swarm. You will get it eventually. You want to concentrate on a combination of spreading out as fast as possible (picking the color that will increase the swarm the most), and quickly diving into new area. Try to avoid picking the same color often. Ex: Red, then Green, and then Red again. It may look like it is the best move, but you should probably pick another color in-between.
Like many of the other games, simply completing the most levels does not necessarily lead to a high score. You must complete each level as fast as possibly for the best score.