Backyard Baseball 2007 is a baseball game with kids, including young versions of, at the time of release, active MLB players. The graphics are on the cartoony side and the play on the field mostly arcade oriented. The majority of time is spent with batting or pitching which rely on timing, there is also active fielding and management of the base runners. Power-ups can be activated when the power meter is filled up and give certain advantages, e.g. the "split ball" power-up for pitchers causes the ball to divide into two. There are various difficulty options which can be turned on or off like automatic fielding or deactivating bat aim (when activated, the player actively has to aim into the direction the ball is supposed to fly).
The game modes are quick matches (also available for two players), a season mode with the ability to change the lineup and some statistics and two mini games (Home Run Derby and Fielder's Challenge which is basically fielding training). The player can either use pre-defined or customized teams and some things (e.g. the young MLB athletes or better leagues to play in) have to be unlocked by completing achievements.