how to play?

You are a green triangle shooting bullets, and the objective is to shoot the red squares, while dodging them. Squares spawn from the topmost part of the screen, and move down. Hit a square five times to destroy it, and gain 10 points. As more points are accumulated, the speed of the squares move faster. You lose when you bump into a square. Level 2 features green squares. Destroying it will take away 5 points. As a result, the square's speed move slower.