Lego Loco Holiday pieces
Set the system date to December 25 for Christmas pieces, October 31 for Halloween pieces, and July 4 for desert pieces.
Ghost train
Set the Windows system clock to October 31 and watch for the ghost train.
Winter time
Press [Caps Lock] before playing a game.
Create a big fountain
Place four fountains in a square to create a single large fountain.
Space shuttle launch pad
Place two radar stations next to each other to create a space shuttle launch pad.
Giant robot
Place a Large IG tower next to a radar station to get a giant robot.
Loch Ness monster
Place a normal pond anywhere on the map. Then, place sunflowers surrounding the lake and Nessie will visit.