Backyard Baseball is a baseball sports video game designed for and aimed at children. There are three main modes: Pick-Up Game, League Play and Batting Practice. A spectator mode exists which pits two randomly chosen computer-controlled teams together. The player can also view their trophies won, their records and view baseball cards of the characters. Before playing a pick-up game or starting a season, the user can change the set difficulty, toggle tee-ball (in Pick-Up Play only), switch from 6- or 9-inning games, and toggle errors. In both modes, a player can create their own team by customizing their team's name and color and drafting 9 players from a pool of thirty characters. During the game, there are many powerups that can be used either by a pitcher, which can be achieved by recording a strikeout, and by the batter, which can be achieved by getting a hit on a power-up pitch when playing offense.
In the pick-up play mode, the player can choose a field from seven different fields of varying size and field material: for example, the field Tin Can Alley makes it unique, due to its hard surfacing and difficulty to score a usual home run. After creating their own team, the player takes turns drafting their players against a computer. In league play, the player is restricted to Parks Department Field No. 2.