If you want to see all the different seasons in LOCO without waiting a whole year, just change the system clock to the appropriate dates
Christmas Day
Easter Day
Summer (the few weeks around midsummer)
Halloween
Ghost Train
To see a ghost train, set your computer's date to October 31st. Now, open LEGO Loco, build a special tunnel, and watch the rails!
Launchpad
You can place a launchpad on the map, even though it isn't listed in the toybox! Here's how:
Put 2 Radar Stations right next to each other.
Close the toybox.
The radar stations transform into a launchpad!
Loch Ness Monster
To see a Loch Ness Monster in the lake, just surround the lake with sunflowers. A Nessie will surface!
Magic Fountains
Place four small fountains in a 2x2 arrangement. They will turn into a giant fountain and create a magic rainbow.
Mansions
To get mansions, first go to toy box and click red houses and put two together. Close the toy box and watch the two red houses becoma a mansion.
Pizza Car
To get a Pizza Car, place a boiler by a road. NOTE: It takes a few minutes for the cars to appear.
Red Car
To get a red car, place a gas station by a road. NOTE: It takes a few minutes for the cars to appear.
Robo Loco
You can place a giant robot on the map! Here's how:
Place a radar station to the right of the tall building marked IG on front.
Close the toybox and wait a little.
The office building is now a giant robot!
Secret Pieces
Fast foward your clock on the computer to all the major holdays, or every month. Then you will have christmas trees, pumpkins and all kinds of holiday pieces.
Space Shuttle Launch
Build a path next to the launch pad (as described by eco-mono) and send lots of people to visit it. Eventually it will take off!
Yellow Car
To get a yellow car, place a house with red bricks on the bottom and blue 3-d glass. NOTE: It takes a few minutes for the cars to appear.