Hunter: The Reckoning Cheats (GameCube)

To get all weapons, during gameplay press UP, DOWN, X, Y, Y.

When playing, have two players access a permanent increase Glyph (either Strength or
Accuracy) at the same time and the Glyph will always be available.

The regular Glyphs (Health and Conviction) are disabled on the fourth use; if one player
uses a Health Glyph three times, have two people use it at the same time for the fourth
time to enable the glitch.

Rescue at least 50 innocents.

Completing the game unlocks two new game modes: Nightmare Mode and Ultimate Hunter Mode. 
Both can be activated by going to the Special Features Menu.