MAG!!! puts the player in the place of the lead editor and publisher of a computer games review magazine in the late 1980s/early 1990s. Up to four players can take turns playing MAG!!!. There are three ways to win the game, one of which has to be chosen at the start of the game: being the publisher with the greatest market share, net worth or score.
Players can choose to publish magazines for IBM-PC, Amiga, Atari ST, C64 or CPC computers. Other vital decisions include choosing publishing in black and white or colour, selecting the right kind of editors to work for the player's magazine and what columns to include in the magazine. It is also important to stay in contact with game publishers since they might provide the player with exclusive games to review. Depending on the difficulty selected at the beginning of the game, players have between 13 and 5 minutes to complete one month's issue.