Krazy Ivan
Level Select: At the Arena Select screen with the globe in the background,
highlight Russia, press R, but before the Japan mission information
appears, press X + D/L (and hold them). The globe will bounce through
different arenas, release the buttons at the one you wish to
play.
The King of Fighters '95
Play as Kunsanagi and Omega Dural: At the Game Select screen, pick Team Play. Pick Team Edit at the next screen. At the fighter-select screen, press and hold Start and press Up and Circle simultaneously, Right and Square simultaneously, Left and X simultaneously, Down and Triangle simultaneously. Two new characters, Kunsanagi and Omega Dural will appear. Now you can play as these boss characters.
Team Match with Three of the Same Character: At the "Game Select" screen, pick "Team Play." Pick "Team Edit" at the following screen. When selecting your fighters, press and hold Start and do the following: press Down and Triangle simultaneously, Left and X simultaneously, Right and Square simultaneously, Up and Circle simultaneously. You should hear a sound. Now you can pick the same fighter up to three times. This also works in the two-player mode.