Mario Tennis (Game Boy Color)

Mario Tennis
Also known as: Mario Tennis GB (JP) Developer: Camelot Software Planning Publisher: Nintendo Platform: Game Boy Color Released in JP: November 1, 2000 Released in US: January 16, 2001 Released in EU: February 2, 2001 Released in AU: February 2, 2001 This game has unused music. This game has debugging material. This game has regional differences. This game has revisional differences.

Mario Tennis is the GBC tie-in to the Nintendo 64 game of the same name. This one has a story mode thrown into the mix, along with a slew of human characters, most of whom haven't shown up since.

Debug HUD

Set RAM address $FF9E to 02 or use GameShark code 01029EFF. This will enable a debug display function. The double speed switch function is called which is required to render the game and output the information of the previous frame simultaneously.

(Source: nensondubois)

Debug Menu

GameShark code 01019EFF enables a debug menu, accessed by pressing A once the player can move around in story mode.

Scene

Map Select. Choose a map with the D-Pad, then press A, B to go to the chosen map. The debug rooms below can also be accessed from here.

To do: Figure out what "- ENTER NO -" does.

Level Up

Does exactly what it says on the tin, allowing both the player and their doubles partner's stats to be leveled up.

Palette

Edits the palette of the current room. Use the D-Pad to choose a color, A to display the chosen color's RGB values, and the D-Pad to edit them.

Flags

Flag editor. Use the D-Pad to select a flag and A to enable/disable it.

To do: Find out what each flag enables.

Debugging Material

There are three debug rooms and one menu in this game. They can be accessed via the scene select in the debug menu, or by editing ROM address $40A9, or by using the Game Genie code ??0-A9B-E6A where ?? is one of the following IDs, then resetting the game.

Development

ID: 01

An empty room featuring with a star background. What it may have been used for is unknown.

Small Char. Test

ID: 02

As its name implies, this room tests the sprites for the story overworld. There are 12 characters strewn across the field. Talking to Alex causes the player's sprite to be cycled through the four main players. Talking to Waluigi (top) makes the player's sprite cycle through every character's sprites, starting with Mario. Yoshi makes your character nod their head. And Bowser makes your character shake their heads. Talking to any of the other characters seems to do nothing.

Test

ID: 03

Another room with lots of characters, each with functions. Any matches won with this has sepia-toned screens with the text "You did it!", and then you're brought back here. Also, any time you lose a Mini-Game with this, the same screen shows up, saying "You failed... Error Code 0".

• Green Girl - Choose from the Story Mode Singles matches.
• Green Boy - Choose from the Story Mode Doubles matches.
• Green Shadow-Server - Choose from the Training matches.
• Green Cat - Says "You two are good. I'll admit that... But remember this." Possibly a text test.
• Leg-Lifter (Left) - Choose from Mario Mini-Games.
• Leg-Lifter (Right, Top) - Plays Credits with game clips.
• Leg-Lifter (Right, Bottom) - Plays Credits without game clips.
• Emily - Goes to the Story Mode character select screen. Whichever character you choose, you'll change into.
• Great Fairy of Victory - Shows the tournament charts. After seeing both Singles and Doubles, the game stops.

Test 2

ID: 04

A sepia-toned menu that seems to not really function. It's likely that most of its features were removed before the game's release. The only thing it does besides crash the game is transport you to the Training Court, facing one of the three coaches. Given this function, this was probably an area select for the Story Mode areas.

(Source: nensondubois for accessing the test rooms and menu.)

Unused Audio

Track 7

Track 23

Track 24

Track 42

Where these tracks may have been used is a mystery. Tracks 23 and 24 are located among the minigame themes in the game's music file.

Regional Differences

Title Screen

Japanese	International

In addition to the background, the Japanese version has different subtler animation.

Dictionary Cover

Japanese	International

The dictionary cover has quite a few differences between regions. The logo was (obviously) changed, the large "T" on the cover was replaced with a tennis ball, and the girl is in a different pose.

3DS Virtual Console/Nintendo Switch Online Changes

The 3DS Virtual Console release of the game does not support the game's Transfer Park functionality. As such, Yoshi/Fruit Fantasy, Wario/Treasure Box, Waluigi/Medallion Match, Bowser/Two-on-One, and the Warehouse court cannot be unlocked if playing this way.

The Nintendo Switch Online release also does not support the game's Transfer Park functionality, however it compensates for it by making all of the above (except the Warehouse court, which is unlocked by defeating every Mario character in an exhibition match) available by default.