Function
Press the "Plus" icon on the Wii remote to enter the pause menu and enable new cheat codes. If you accidentally press a button while in the pause menu, just un-pause and re-pause the game to reenter the cheat successfully.
Considerations
The Wii Nunchuk must be connected to enter codes properly. If you are using a Gamecube controller or Classic Controller, simply switch in the Nunchuk to enter the codes.
Weapons
Press up, down, up, down, left, right, left, right, Z, Nunchuk analog down, Z and Nunchuck analog down to open up the Swordfish weapon.
Press left, left, right, right, Z, Nunchuck analog down, Nunchuck analog down, Z, up and down to open the Baby Toy weapon.
Press right, left, right, left, down, down, up, up, Z, Nunchuck analog down, Z, Z, Nunchuck analog down and Nunchuck analog down to open the Telephone Sword.
Press up, up, down, down, left, right, left, right, Z, Nuchuk analog down, Z and Nunchuck analog down to open the Chainsaw.