These work for the US version of the game. [RSBE01]
These are my very first codes, so tell me if they have bugs.
Invincibility: Makes you invulnerable to all attacks.
Punching-Bag: Allows other players to knock you off-screen with one hit.
One-Hit Kills: Allows you to knock other players off-screen with one hit.
Gravity Screw-Up: Player floats up when they re-spawn.
Player X Invincibility: [WiiMaster]
4A000000 XXXXXXXX
140000D0 CCCCCCCC
E0000000 80008000
Player X Punching-Bag: [WiiMaster]
4A000000 XXXXXXXX
140000D0 4479C000
E0000000 80008000
Player X One-Hit Kills: [WiiMaster]
4A000000 XXXXXXXX
140000CC 4479C000
E0000000 80008000
Player X Gravity Screw-Up: [WiiMaster]
4A000000 XXXXXXXX
140000E0 C0000000
E0000000 80008000
X Values:90180F20 = Player 1
90180F7C = Player 2
90180FD8 = Player 3
90181034 = Player 4
Long-Legged Pikachu: [WiiMaster]
077DCFF8 00000008
2FD78C71 00331F00
Do NOT use the Up + B Move!I don't know why this happens, but in the level of Subspace Emissary where you play as Zero-Suit-Samus, the game stops loading, but doesn't freeze... so you can restart it.