The King of Fighters '99 Cheats

At the Character selection screen,go to the Random Select,press and hold start then do:

For Kyo:Left,Right,Up,Left,Down,Right

For Iori:right.Left,Up,Right,Down,Left

There are three special custom team endings in KOF99.

Kyo Team Ending: Unlock Kyo and have him on your team to get the team ending. It doesn't matter if you have unlocked Iori or not.

Iori Team Ending: Unlock Iori and have him on your team to get the team ending. It doesn't matter if you have unlocked Kyo or not.

Kyo+Iori Team Ending: Unlock both Kyo and Iori and have both on your team to get the team ending.

Hold START while selecting your characters's order. You'll see their picture instead of the usual question mark.

Immediately press a button after beating the opponent.
Each button will make you see a different winning pose.