I remember playing this game in grade school and it was a fun and addicting experience. Each mission consists of navigating through these outer space fortresses and making it out alive before they blow up. I recall getting very sweaty palms because the screen would vibrate slowly and gain intensity as the time limit nears its end. Each fortress increases in size and complexity as you progress through the game. Lots of trial and error in the beginning but as you replay the game over and over you can become an expert and not mind going through it again and again. TONS OF FUN!!!