Great things to say about this game are its crisp graphics for the day, physics, and smooth game play. In addition to turning and shooting, there's thrust to move and 'hyperspace' to vanish and re-appear in a random location. Both thrust and hyperspace can get you out of a fix in a hurry, but the risk is high of ending up in a worse-off spot. U. F. O.s add flavour and points to the mix as well.
Controls needed the most help, everything was button based whereas a joystick would've really come in handy and be a more natural fit. There's no on-screen intro, story, or conclusion to the game which isn't necessarily a surprise for the day but would certainly motivate a player to succeed or at least keep coming back.
Important arcade game in history, well worth a few quarters.