Invincibility:
Quickly type "alakazam" when "Press Jump" appears at the first screen.

Slow motion mode:
Press [F2] to pause game play and highlight the "Continue" option. Hold [Enter] to advance the game frame-by-frame. Repeatedly hold [Enter] to play in slow motion.

Cheat mode:
Pause game play, then enter one of the codes:

Result - Code:

Hovering gadget - jets online
Unlimited Green Laser - laser
All gadgets - lightyear
All Pizza Tokens - cheese pizza

Jump on the car:
Get on the rafters and you will see a coffee cup. Jump on that, then jump on the lights. You can then jump on the car and get the green laser.

Hidden tips:
Collect 100 or more coins in the first level, Andy's House. Give the coins to Hamm. He will lead you to a room called Woody's Workshop. This room contains more hints and tips about defeating Bosses, etc. Note: If you have already given Hamm 50 coins, this will not work.