Grade: C- (71.78)
I used to sing the theme song to Vanguard when I went to bed each night. You must pilot the ship through a bunch of different caverns, shooting aliens.. The memorable aspect of Vanguard is the ship, which can shoot in all 4 directions. If you fly through an energy pod, you become invincible and can simply crash into the enemy ships while the song plays. When you reach the end of the cavern, you must shoot the Gond, which is just a big face. Unfortunately, it is way too easy to kill the Gond in this version, which was not the case in the arcade.
Images from www.atariage.com (used by permission)
Descriptions from www.atariguide.com (used by permission)