Knife Edge: Nose Gunner [N64]
Hold L + R +C-Up, then press C-Right, C-Left, B at the Kemco logo. A "Super Hard" difficulty setting may now be selected.
Select "Story" or "Team" mode, then hold C-Left + C-Right + C-Up + C-Down + R and press Right, Up, Left, Down when the level number is displayed.
Tougher Difficulty = As the Kemco logo qppears on-screen, hold R+L+C-Up, then press C-Right,C-Left, and B