Luigi in Adventure Mode:
To fight against Luigi instead of Mario, finish the Mushroom Kingdom stage by crossing the goal line when the timer's seconds is at a 2. Example: 3:12.

After you finish the first level in Adventure mode (Mushroom Kingdom), you normally fight against Mario and Peach. But you can also fight against Luigi Instead of Mario.

Giant Kirby in Adventure Mode:
To fight Giant Kirby, finish the Kirby Team stage in less than 30 seconds.

After you fight the Kirby team in Adventure mode, you can fight a Giant Kirby.

Falco in Adventure Mode:
Falco appears randomly in this battle after he is unlocked as a playable character.

In your rematch aboard Great Fox, you will sometimes fight Falco instead of Fox McCloud

Giga Bowser in Adventure Mode:
Play Adventure mode on Normal or Harder, and beat all 12 stages within 18 minutes, without continuing.

After your showdown with Bowser in Adventure Mode, if you met the right conditions, you will then meet Giga Bowser.

Crazy Hand in Classic Mode:
Play Classic mode on Normal or Harder, and beat all 10 stages within 15 minutes, without continuing.

Halfway through your battle with Master Hand, if you met the right conditions, you will do battle with two hands at once.

All Star Mode:
Unlock all 25 characters.

This mode challenges you to defeat all of the games characters, in one life.

Score Display:
Earn a combined total of more than 5,000 KO's

In timed mode, this will enable you to see the points you've earned near your damage meter.

Random Stage:
Unlock the following levels: Brinstar Depths, Fourside, Big Blue, Poke Floats, Kingdom II, and Flat Zone

This will enable you to have the computer select a stage for you in VS Mode. Just pick "Random Stage" on the arena select screen.

Sound Test:
Unlock every stage and character.

A basic sound test, that includes every music track and sound effect from the game.

Mew from a Pokeball:
Unlock every character.

Mew will come out of a Pokeball randomly, with a 1 in 251 chance.

Celebi from a Pokeball:
Unlock everything - Characters, Sound Test, Randon Stage, and Score Display.

Celebi will come out of a Pokeball randomly, with a 1 in 251 chance.