|Better Chance Of Winning|
When playing against the CPU, if you win a game or a set in the match, save the game, then continue the game. In case you lose, you can continue from the saved game and start with the advantage.
Win the Star Cup/Doubles Tournament with Birdo.
|Bonus Difficulty Level|
Win the Planet Cup with all sixteen players to enable the max difficulty setting in exhibition matches.
|Donkey Kong Court|
Win the Mushroom Cup/Singles Tournament with Donkey Kong.
Win the Star Cup with a character. Then at the character selection screen, hold R while selecting that same character to make them have handicaps and be more powerful. If done correctly, a yellow star will appear in the bottom right of the screen (for player one) or bottom left of the screen (for player two). Press L + R to have a left-handed player that is also a star character.
At the character selection screen, hold L while selecting a character to make them left-handed.
|Mario Brothers Court 2|
Win all the Doubles Tournament Cups with Mario.
Note: This is another Mario Brothers Court, but not the alternate way to get the previous one.
|Mario/Luigi Castle Court|
Win the Star Cup Doubles and Singles Tournament with Mario.
Win the Mushroom Cup/Singles Tournament with Mario.
|Nintendo Ring Tournaments|
Select the "Special Games" option at the main menu, then choose the "Ring Tournament" selection. Enter one of the following codes to play in the corresponding tournament for the indicated Cup.
Note: Another code will be displayed after completing the tournament. The new code is not actually a code for the game, but is for ranking you with other players at Nintendo's Mario Tennis web site.
|Piranha Plant Court|
Note: This court only works in Piranha Plant Challenge. Complete any court (perfect, all 50 balls) in the Piranha Plant Challenge with any character.
|Play As Donkey Kong Jr.|
Win the Star Cup/Doubles Tournament.
|Play As Shy Guy|
Win the Star Cup/Singles Tournament.
|Restart Replay During Demo|
Wait at the title screen until the demo begins. Press B to restart the replay. Any other button will end the demo.
|See The Same Replay Again|
Press B while in a replay to see the replay again at different angles. This can be done at any point of the replay for as many times as desired.
Win all the Tournament Cups with all the characters (including Shy Guy and Donkey Kong Jr.) to unlock the Special Cups, which are much harder than the previous ones. Press R while selecting a character at the character selection screen to access the Special Tournament in the menu. The three Special Cups in order are Rainbow Cup, Moonlight Cup, and Planet Cup. Once you win a Cup, you will move onto the next one.
|Wario Brothers Court|
Win all the Doubles Tournament Cups with Wario.
|Yoshi/Baby Mario Court|
Win the Mushroom Cup/Singles Tournament with Yoshi.