Mario Tennis

Nintendo Ring Tournaments
At the main, choose the "Special Games" selection, then select the
"Ring Tournament" option. Enter the following cheat codes at the
code entry screen:

Play tournament for Wario Cup: Enter "UOUFMPUOM"
Play tournament for Waluigi Cup: Enter "LA98JRLAR"
Play tournament for Peach Cup: Enter "OF9XFQOFR"
Play tournament for Nintendo Power Cup: Enter "J6M9PQJ6U"
Play tournament for MarioTennis.com Cup: Enter "48HWOR482"
Play tournament for Mario Cup: Enter "A3W5KQA3C"
Play tournament for Luigi Cup: Enter "M1C2YQM1W"
Play tournament for IGN64 Cup: Enter "V2UFMPUZM"
Play tournament for Donkey Kong Cup: Enter "MM55MQMMJ"
Play tournament for Bowser Cup: Enter "N24K8QN2P"
Play tournament for Blockbuster Cup: Enter "ARM6JQARU"

Unlock Birdo/Yoshi court:
Win 1st place on the Star Cup/Doubles Tournament with Birdo.

Unlock Donkey Kong court:
Win 1st place on the Mushroom Cup/Singles Tournament with Donkey Kong.

Unlock Mario/Luigi Castle court:
Win 1st place on the Star Cup Doubles and Singles Tournament with Mario.

Unlock Mario/Luigi court:
Win 1st place on the Mushroom Cup/Singles Tournament with Mario.

Unlock Wario Brothers court:
Win 1st place on all the Doubles Tournament Cups with Wario.

Unlock Yoshi/Baby Mario court:
Win 1st place on the Mushroom Cup/Singles Tournament with Yoshi.

Unlock Donkey Kong Jr:
Win 1st place on the Star Cup/Doubles Tournament.

Unlock Shy Guy:
Win 1st place on the Star Cup/Singles Tournament.

Left-handed character
Hold L while selecting a character at the character selection screen.

Unlock Mario Brothers court 2:
Win 1st place on all the Doubles Tournament Cups with Mario.

Hardest difficulty level
Win 1st on the Planet Cup with all 16 players

Unlock Special Cups
Win 1st palce on all the Tournament Cups with all the characters (including
Shy Guy and Donkey Kong Jr.)

Piranha Plant court
Finish any court (perfect, all 50 balls) in the Piranha Plant Challenge with
any character. Note: Only works in Piranha Plant Challenge.