Boxer is a platform game written by Wal Mansell. You and your computer controlled rival are competing for the attentions of a young lady. At the bottom of the screen, she is releasing balloons which you must try to catch when they get stuck in the rafters of the Gym. Any balloons which escape to the top of the screen will be awarded to your opponent. If you collect five balloons before your opponent does, your score will be increased by the bonus in the top right-hand corner of the screen, and you will move to a more challenging Gym. If your opponent is the first one to collect five balloons, you will lose a life and stay in the same Gym. You can only catch balloons safely while they are caught in the rafters. If you try to grab or touch one while it is moving you will fall over. This will also happen if you have contact with your opponent or any of the boxing gloves, hammers or dumb-bells which move across the Gym. Every time you get three falls, you will lose a life. Gloves and hammers can be punched and dumb-bells jumped over to score points. Points can also be scored by jumping up to the punch balls at the bottom of the screen.
You start the game with three boxers but you will receive a bonus boxer for every 10,000 points you score, up to a maximum of three at any one time.