• Play Luigi's Shooting Star mini-game and win both levels. When you get to the third level, beat the high score of 60. You can now play on the Castle Court in linked play and exhibition modes.

Tropics Court:

• Play Baby Mario's Target Shot mini-game and win both levels. When you get to the third level, beat the high score of 60. You can now play on the Tropics Court in linked play and exhibition modes. 

Jungle Court:

• Play Donkey Kong's Banana Bunch mini-game and win both levels. When you get to the third level, beat the high score of 60. You can now play on the Jungle Court in linked play and exhibition modes.

Play as Students:

• Defeat the students you face in the Junior, Senior, Varsity, and Traveling Leagues to unlock them at the character selection screen.

Play as Peach: Win the game in Doubles
Play as Mario: Win the game in Singles

Nintendo 64 characters:

• Use the Transfer Pak with the Nintendo 64 version of Mario Tennis. Select "Transfer" at the main menu, then select "Game Pak Check". After it checks, an icon that says "Transfer N64 Characters" will appear. This will allow you to play as Bowser, Waluigi, Wario, and Yoshi.

More mini-games:

• Unlock the Nintendo 64 characters, then check the mini-game screen. More entries should be available. To unlock even more mini-games, win the Junior, Senior, Varsity, and Traveling Leagues in Singles and Doubles.

Silver and Gold rackets:

• Equip the Iron Racket, and go to the training courts. Head up to the lake and follow along the edges until you see a boy  practicing his swing. Tell the boy that you don't like it and you will show him your swing. He will laugh making you angry.  Get ready to swing. In ten seconds, press the A button as many times as possible. Press it 100 times and you will get the  Silver racket. Press it 150 times and you will get the Gold racket.