Say “Groovy”:
After completing a level, tap ‘Square or X to cause Jim to say “Groovy!” as many times as desired, delaying the start of the next level indefinitely.

Trophies:

Bronze trophies
Bin collector – Kill Billy the Bin in New Junk City.
Atom Raider – Collect 100 atoms (without exiting the game).
Atom Jefferson – Collect 500 atoms (without exiting the game).
Canadian stunt – Use the whip to swing from any moose head in Single Player mode.
Banker Whipper – Whip a banker twice in What The Heck?.
Space Collector – Collect more than 100 Blue Orbs (without exiting the game).
Snot a Trophy – Launch the cow in New Junk City.

Silver trophies
Groovy Leader – Be ‘No. 1’ in each PlayStation Network multiplayer level.
Super Space Collector – Collect more than 300 Blue Orbs (without exiting the game).
World Partnership – Complete all the Playstation Network multiplayer game levels.
Superhero! – Get through Single Player mode in Original difficulty in one sitting in under 50 minutes.

Gold trophies
Earthworm Never Dies – Clear Single Player mode in Original difficulty in one sitting without losing a life.