Hexen (N64)

To access the Cheat Menu:
Pause the game. Press C-Up, C-Down, C-Left and C-Right.

Input the following quickly in the Cheat Menu

God Mode: C-Left, C-Right, C-Down.
Level Select: C-Left, C-Left, C-Right, C-Right, C-Right, C-Down, C-Up.
Butcher (instant kills): C-Down, Top C, C-Left, C-Left.
Health: C-Left, C-Up, C-Down, C-Down.
Walk through walls: C-Up(20), C-Down.

Input the following in the Collect Menu
All Keys: C-Down, C-Up, C-Left, C-Right.
All Artifacts: C-Up, C-Right, C-Down, C-Up.
All Weapons: C-Right, C-Up, C-Down, C-Down.
All Puzzle Items: C-Up, C-Left, C-Left, C-Left, C-Right, C-Down, C-Down