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!

Blueprints:
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