From the main menu select GAME, then select JUMP TO. Press ALT-F5 and you can JUMP 
to ANY scene. Use the up-down buttons to see all the new jump opportunities. 
Submitted by Paul Haigh DaChief @ Surfsquad.com 

Skip puzzle
Hold Alt and Shift. Then press the first letter of the name of the puzzle. 
Note: The exception is the Orbit puzzle, which is skipped by pressing Alt and Shift 
      and I. 
Submitted by unknown