mine feild
in the mine feild to get across to the houses u have to shoot down the bed mattrasses hanging from the crane and use pancake to get on the first matrass. Watch out for the ball thingy, it shoots electric eggs.

The last window
I was just playing the Grinch and I had the hardest time finding the last window that I had to launch my egg into. If you have the same problem, go the way you want to go back to the mountain and right above the transporter is the final window. All the others should be easy.

Level Skip:
Go to the gadget screen and press X while holding R1.

Mini-Games:
Destroy the mentioned number of gifts. Afterwards climb to the upper level of Mount Crumpit to access the chosen mini-game:

Spin 'n' Win .... 750 gifts
Pankamania .... 1500 gifts
Copter Race Contest .... 2500 gifts

Bike Race:
Destroy 3,000 gifts and complete the whole game. Look behind the bookcase in the workshop with the sleigh to access the Bike Race mini-game.

The Gadgets:
Binoculars .. whoville .. 4 blueprints
Rotten egg launcher .. whoville .. 4 blueprints
Rocket spring .. whoforest .. 9 blueprints
Slime shooter .. whoforest .. 9 blueprints
Octopus climbing device .. the dump .. 9 blueprints
Marine mobile .. wholake .. 16 blueprints
Grinch copter .. every level .. 16 blueprints

City hall:
To get into City Hall shoot the big clock and the door will open.

Small white walls
In Downtown Whoville, there are small white walls in various places. Use your rotten egg launcher to shoot the walls and they will break and reveal one or more gifts and a rotten egg plant.