Concept art:
Get a Platinum Medial in Challenges #1, #3, #5, and #7 to unlock concept art 
pages. 

Hidden FMV sequences:
Complete Challenge #21 to unlock the "Original Promo Movie" and "Deleted 
Scene - Crivens Gives The Chair" options in the replay storybook.

View credits:
Successfully complete the game, and you can view the staff credits at 
the "Features" menu of the game.

Get extra health:
Enter the options screen and enable the "Butler's Brew" option. Now if you fall in 
any room, you will be given an option upon re-starting that room if you want 
Coffee and Waffles. Press A to select "Yes" and you will have double health.

Banjo-Kazooie references: 
You can see various pictures and statues of Banjo-Kazooie's "Mumbo Jumbo" in 
the rooms of the mansion.

Whenever you fight a "Ghoulie", listen. They often sound like creatures from Banjo-
Kazooie.

Every time you enter the kitchen where Ma Soupswill is located, look on the 
billboard near one of the kitchen's doors. You will see a picture of Banjo and 
Kazooie.

Rare and Microsoft references:
When you start a new game, look at the three books that are shown. One 
says "Rare" and the other says "Microsoft". If you look closely, you can see that 
when "Rare" books pages are turned, there are pictures of Banjo Kazooie and 
Donkey Kong Country. In the "Microsoft" book, you can see an Xbox, an Xbox Live 
microphone, and other Xbox items.

Mini-games:
For every five "Rare books" that you find, you will unlock a bonus mini-game at 
the mini-game screen. There are 100 "Rare books" in the game, which unlock a 
total of twenty bonus mini-games. There is one "Rare book" in every room of the 
mansion.