Mario Superstar Baseball[b] is a 2005 sports video game developed by Namco and published by Nintendo for the GameCube.

[1] Gameplay mainly focuses on the player assuming the role of many Mario series characters to challenge any opposing teams compatible in the Challenge Mode, the final being Bowser, having baseball matches to see who will win the Cup of the mode.

Other playable modes include Exhibition Mode, in which players choose the leader and the other rosters in the team and challenge another team to a single baseball game, and Minigames where the player must complete a certain mission.

For example, aside from the aforementioned captains and sub-captains, Mario's team consists of Monty Mole, 3 Piantas, and 3 Nokis, Princess Peach's team consists of Toadette, Toadsworth, and 5 Toads, Wario's team consists of Boo, King Boo, Petey Piranha, and 4 Magikoopas, Yoshi's team consists of Baby Mario, Baby Luigi, and 5 Shy Guys, Donkey Kong's team consists of Dixie Kong, Goomba, Paragoomba, 2 Paratroopas, and 2 Koopa Troopas, and Bowser's team consists of 4 Dry Bones, Hammer Bro, Fire Bro, and Boomerang Bro (although Hammer Bro, Fire Bro and Boomerang Bro are separate characters (enemies) in the Mario series, in this game, it is actually just a color variation of the same character.).

If the player wins a game in this fashion, all characters on the opposing team will be so impressed that they will immediately join.

There is a shop located on the map for purchasing power-ups, each worth a certain number of coins that the player earns from the minigames or Bowser Jr.

Other power-ups offer a temporary boost to a stat for all characters on their team, but they only last for one game, win or lose.

Another goal during Challenge Mode is the Superstar quest; each character has a set of requirement that earn stars.

The game rules that cannot be changed are as follows: Your team bats first, and the Star Skills and mercy are turned on.

[3] Robert Workman of GameDaily praised the game, writing, "...I found [Mario Superstar Baseball] to grow on me.