To Skip A Puzzle
Use ALT-SHIFT and the first letter of the puzzle's name. For example, to skip the Probe Logic Circuit Puzzle by pressing ALT-SHIFT-P. The exception is the Orbit puzzle- use ALT-SHIFT-I. The code is different for each puzzle.
To Jump To Any Part Of The Game
From the Main Menu select GAME. Hit ALT-F5. Pick JUMP TO and it will show thumbnails of various scenes in the game. Click on one to jump to it.