Grabbed by the Ghoulies Game Cheats

Unlock Concept art:
Earn a Platinum Medal in the following challenges to get access to concept arts:
Challenge #1
Challenge #3
Challenge #5
Challenge #7

Secret movies - Promo and Deleted Scene FMV sequences:
Finish Challenge #21 to unlock the secret movie options in the replay storybook.

Staff credits:
Finish the game once to watch the staff credits at the "Features" menu.

Bonus health:
Enable the "Butler's Brew" option in the options menu. If you can't complete any room, you will be given a restarting optionfor that room if you want Coffee and Waffles. Hit A button to choose "Yes" and you will get double health.

Unlock mini-games:
If you find 5 Rare books, that will unlock one bonus game at the mini-game screen. To unlock all 20 mini games, you have to collect all 100 rare books.