is an alright action game made by Japanese developer f1ash. Your objective is to protect the eye in the middle of the screen from enemies which explode on contact.
Destroy circles, bugs and rockets by drawing a square around them, or drag any object around by left clicking. You will experience a shot delay after each time a box is drawn, and having the eye inside the square damages it as well.
Collect power-ups by dragging and dropping them onto the eye. The easy and normal mode ends when the tank is beaten.