View credits
Successfully complete the game once to unlock the "Credits" option.

Level select
Successfully complete the game twice (select a different artifact
in Roman Dude's stage) using the same saved game file to unlock
the "Jump To Game" option.

Invincibility
Successfully complete the game three times using the same saved
game file to unlock Eternal Mode under the "Jump To Game" option.

Secret ending
Successfully complete the game three times using your same saved
game data when starting a new game each time to view a special ending
movie the third time the game is completed.

Skeleton screen
At the main menu, select "Options" and the picture of Alex will
turn into a skeleton.

Invisibility
Use the Reveal Invisible spell with the Mantorok Rune to make your
character invisible.

Recovery
When you learn the recover spell, use Chattur'gha (Red) to recover
your health, Xel'lotath (Green) to recover your sanity, or Ulyaoth
(Blue) to recover your magic.

Defeating zombies
If you have a torch and you are face a large group of zombies, swing
the torch at them. They will die in one hit. You will have to do
a final blow quickly because they will disappear if you are too
slow. Note: This will only work on the normal common zombies.

Mantorok Rune
When playing as Dr. Lindsey, find the two Runes for Summon and Creature.
One is found in a zombie on the staircase down on the last floor
and another is on the last floor in some cobwebs. Use your archeological
brush to uncover it. Combine these two runes together to make the
Summon Trapper spell. Go back up to the floor with the gold statue
and find your way to the machinery that was uncovered when you dispelled
all the magick fields. When you examine it, you will learn that
there is a hole small enough for a small dog to walk through. Summon
a Trapper to walk through the hole. Inside will be a bridge with
two Horrors on each side. Walk past them and onto a switch with
a purple Rune on it. Press A to kill the Trapper and take control
of Lindsey again. The switch will have opened a door behind you,
where the Mantorok Rune is located.

Special Ending
At the end of the game, you can choose one of three artifacts. Beat the game
three times and keep choosing a differemt artifact. When you beat the game for
the third time, you'll get a big special ending.