Mario Tennis 64 Codes -

All characters and courts:
Note: This does not unlock the Mario's Star court, and will delete all your saved accomplishments; it marks all of the goals as completed, including a gold star on all of the Ring Shot challenges. Press (x2), (x3), (x3), (x2), (x3), (x3) when "Press Start" appears at the title screen. A sound will confirm correct code entry.

Nintendo Ring tournament:
Press at the title screen. Highlight the letter S (Special Games) in the center of the bottom row and press . Highlight the trophy (Ring Tournament) icon, which is the third from the left and press . Enter A3W5KQA3C as a password to play a tournament for the Mario Cup. Another password will be displayed after completing the tournament. The new password is not actually a password for the game, but is for ranking you with other players at Nintendo's Mario Tennis web site. Other passwords include the following.

Enter J6M9PQJ6U as a password to play for the Nintendo Power Cup.
Enter ARM6JQARU as a password to play for the Blockbuster Cup.
Enter V2UFMPUZM as a password to play for the IGN64 Cup.
Enter V5UFMPU5M as a password to play for the Pokemon.com Cup.
Enter 48HWOR482 as a password to play for the MarioTennis.com Cup.
Enter M1C2YQM1W as a password to play for the Luigi Cup.
Enter LA98JRLAR as a password to play for the Waluigi Cup.
Enter UOUFMPUOM as a password to play for the Wario Cup.
Enter MM55MQMMJ as a password to play for the Donkey Kong Cup.
Enter OF9XFQOFR as a password to play for the Peach Cup.
Enter N24K8QN2P as a password to play for the Bowser Cup.
Enter 4YHWOR4Y2 as a password to play for the Mr. Pickle's Cup.
Enter ZKZLZKNNR as a password to play for the Yoshi Cup.
Enter 5G3LTQ5GN as a password to play for the WimbleDonkey Kong Cup.

Left-handed character:
Hold while selecting a character to make him/her left-handed.

Star player/handicaps:
Note: Win the Star Cup with a character (get three cups in a tournament). Hold while selecting that same character to make him have handicaps and make him more powerful. 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 + to have a left-handed player that is also a star character. Being a star player will enable you to serve stronger and play better. If you make Bowser a star player he will be able to serve up to 136 mph. Note: Donkey Kong Jr. and Shy Guy are already star players when they are unlocked.

Rocket shot:
Press + for a rocket shot. This also works when serving. If done correctly, a purple streak will appear after you hit the ball.

Slow shot:
Press , then .

Lob shot:
Press , then .

Control the ball:
This trick can be done with any player, against any player. Hold or as you hit the ball. This will send it in whichever direction you pushed the stick.

Shy Guy:
Win the Star Cup/Singles Tournament. This character can already use the handicap cheat after being unlocked. You do not have to win the Star Cup as this character.

Donkey Kong Jr.:
Win the Star Cup/Doubles Tournament as any character. This character can already use the handicap cheat after being unlocked. You do not have to win the Star Cup as this character.

Game Boy Color characters:
Use the Transfer Pak with the Game Boy Color version of Mario Tennis. Select "Transfer" at the main menu, then select "Game Pak Check". After it checks, select the option to transfer the Game Boy Color characters. This will allow you to play as Alex, Harry, Nina and Kate.

Bowser Court:
Complete the Bowser 2 on 1 mini-game on Mario Tennis on the Game Boy Color, then send the data to the Nintendo 64 with a transfer pack.

Donkey Kong court:
Win the Mushroom Cup/Singles Tournament as Donkey Kong.

Yoshi and Baby Mario court:
Win the Mushroom Cup/Singles Tournament as Yoshi.

Mario and Luigi court:
Win Mushroom Cup/Singles Tournament as Mario.

Mario Brothers court 2:
Win all the Doubles Tournament Cups as 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 as Mario.

Super Mario and Wario Courts:
Win the Mario mini-games for Mario and Wario in the Game Boy Color version of the game. Then, refresh data and send it to the Nintendo 64 through a Transfer Pak.

Wario Brothers court:
Go through all the cups for Double Tournament with Wario.

Waluigi Court:
Win the Medallion Match and set a new high score in challenge mode in the Game Boy Color version of the game. Then, refresh data and send it to the Nintendo 64 through a Transfer Pak.

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.

Birdo/Yoshi court:
Complete the Star Cup Doubles as Birdo to unlock the Birdo/Yoshi court.

Star tournament:
Have all characters a star player to play in the Star tournament.

Special Cups:
Go through 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 one. Press while selecting a character 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.

Unlocking skills levels:
Win the Planet Cup with all sixteen players to enable Max Difficulty in exhibition matches.