Pikmin
In-game reset:
Hold A + B + X + Y + Start during game play.
Challenge mode option:
Save the game at any point to unlock a "Challenge Mode" option
at the main menu. Select that option to replay previously
completed sections in a time attack type scenario. Collect as
many Pikmin as possible before nightfall.
Fireworks:
Press Down to round up four Pikmin to carry you back to your base camp.
A short fireworks display appear. This also eventually happens if
you stand idle.
Invincible Captain Olimar:
Press Down and Captain Olimar will lay down.
He cannot be harmed in this position.
Alternate music:
Remain idle at the level selection menu for about five to ten minutes.
You will hear a different song playing in the background.
This also occurs in Challenge Mode.