Final battle:
Enter HDKFGTFLGFTKCD as a password.

Fighter skip:
Hold A + B + Select and press Start when the picture of the next fighter appears.

Hint: Skinny neck in training:
In training mode, try punching as fast as you can. If done correctly the man's neck will turn skinny and it looks as if it falls off. Note: You have to hit the bags and cannot miss.