As you play, you will notice a giant block moving to the left, decreasing the playfield. It is your job to push it back to the right side. If you succeed, you will get to the next level. In order to push it back, you need to cause as many explosions as possible. You can do this by shooting colored blocks. There are five beams at your disposal. Use the up and down arrow keys to select a different beam, and use the space bar to fire. Whenever you fire with one of the beams, it's power meter will drop. If there is no power left, you can't fire this beam anymore - but only for a short while, because the meter will automatically increase. The blocks that you have to shoot come in three colors; red, green and yellow. You can only shoot blocks that are the same color as the beam they are in. You can change the beam's color with the left and right arrow keys. If one of the colored blocks moves out of the screen before you can hit it, the gian block will move left a bit faster, so try to hit as many of them as possible. If one of the stars (white dots) enters an explosion, it will explode as well, which can cause a chain reaction of explosions, pushing the giant block more to the right.