Music test
Choose the "Name Entry" selection at the options screen. Select "Yes" to enter a name. Do not actually enter a name. Instead, press [L] to display the music test screen.
Scroll faster on grid
You can scroll through the writing faster on the grid by tapping or holding [L] or [R].
Intermission bonus
During a break when it shows a character, press [A] and something will happen.
Control credits song tone
Press [L] while the credit music is playing to increase the bass, or press [R] to increase the treble.
Control credits sequence
Hold [Left], [Right], [Up], or [Down] during the credits to change the star patterns.
Boss mode
Successfully complete the game to unlock an option to fight just Bosses.
Staff mode
Successfully complete the game to unlock an option to view the game's developers..
Chicken Race (two player) mini-game
Defeat any two of the first group of characters.
Chiritorie (two player) mini-game
Defeat anyone in the first group of characters.
Dong Dong (two player) mini-game
Defeat anyone in the second group of characters.
Dr. Wario mini-game
Get 15 mails against Blue Jimmy.
Fly Swatter mini-game
Get 20 mails against Yellow Jimmy.
Hurdle (two player) mini-game
Defeat any two of the second group of characters.
Pyoro mini-game
Successfully complete the Wario stage.
Alternately, unlock all of the mini-games for every character.
Pyoro 2 mini-game
Beat the challenge score on every Microgame.
Paper Plane mini-game
Successfully defeat Red Jimmy.
Wario's Sheriff mini-game
Get 25 mails against Red Jimmy.
Easy mode
Defeat Wario to unlock the "Easy mode" option.
Thrilling mode
Successfully complete the game in easy mode with a high score to unlock the "Thrilling mode" option.
Hard mode
Get at least 15 mails in Thrilling mode.
Alternate menu music
Defeat the second Wario, then view the credits. When the credits are over, the game will return to the main menu. A different song will now be playing.
Skip introduction or opening sequence for level
During the introduction of a level, turn off the Game Boy Advance, then turn it back on. Go to the level that you were just on and you can now press [A] button to skip the introduction.