When constructing your blueprints to your specially designed weapons, always put the key sheet on the bottom page facing the opposite direction and also facing upside down, and if there is a crosshair, then it goes right above the blueprints.
Secret Egg-Launching Window
All of the windows are easy to find except for a singular one. Go to the stage where the Grinch is sucked into his giant cave. Just before you go under the stone-filled arch and into the red vacuum, change your view to look above, Where you will find the missing window.
Bonus Wrapped Presents
In Downtown Whoville, you will find a child that is afraid of you. Before he runs away, use your powered-up "bad breath" attack and the boy will disappear, revealing a 3 point gift!
Reaching high places
If you are having trouble getting to high places, look for a bar and press A. When you are swinging with Y, press A button to make The Grinch jump off the bar.
Look on top of the town's Christmas tree to find a hidden present.
Unlock Spin N' Win Mini-game
After you destroy 750 gifts, the Spin N' Win mini-game will be unlocked. Go to the top of Mount Crumpit to play.
Unlock Copter Race Mini-game
After you destroy 2500 gifts, the Copter Race mini-game will be unlocked. Go to the top of Mount Crumpit to play.
Unlock Pankamania Mini-game
After you destroy 1500 gifts, the Pankamania mini-game will be unlocked. Go to the top of Mount Crumpit to play.
Unlock Bike Race Mini-game
After you destroy 3000 gifts and complete the game, the Bike Race mini-game will be unlocked. Look behind the bookcase in the sleigh workshop to play.