Unlockable: Hard Difficulty
To unlock the hardest difficulty level beat the 3 tournaments of the star cup.

Unlockable: Star Cup
To unlock the Star Cup beat the 3 tournaments of the Normal Cup.

Unlockable Shy Guy (Technique: Tricky)
In tournament mode, beat the normal tournament on all 3 courts.

Unlockable: Paratroopa
Beat all 3 normal tournament cups to unlock this blast from the past.

Unlockable: Color Change Yoshi
After completing the first cup in normal tournament doubles, you unlock this ability for Yoshi. Now every time you do your defensive power shot with Yoshi, he will change colors according to egg color he rolls in.

Unlockable: Piranha Plant
Beat both Special tournaments, Fire and Thunder, in doubles matches.

Unockable: Wiggler
Beat normal flower cup in doubles, to unlock Wiggler (Defense.)

Unlockable: Event Games
When you get to the main menu, push 'B' to go back to the 'Press start' screen, then hold 'Z' and then press 'Start' or 'A' and then Event games will be unlocked.

Note: Every time you restart the GCN you wil have to hold 'Z' again.