This guide is meant only to help players figure out which commentary-level doors can be safely ignored as they chase down the final few World 7 puzzle pieces. Specific routes (some of which are more challenging than the puzzles to which they lead) are omitted. If you want more explicit spoilers on getting to the World 7 puzzles, the current best guide for that is Xealeen’s 100% Achievement Guide.

World 7 jigsaw puzzle with arbitrary numbering scheme superimposed

Arrows (→) represent doors to nested levels.
In the case of Special Topics, some areas are named. One puzzle-level door (corresponding to puzzle piece 15) is found in such a named area.

1. Visual Art → Galleries
   
2. Programming
   
3. Programming
   
4. Design → Monologues
   
5. Visual Art
   
6. Sound & Music
   
7. Design → Monologues
   
8. Design → Casey Muratori
   
9. Design → Monologues → Alternative Designs
   
10. Design → Brian Moriarty
    
11. Design → Brian Moriarty
    
12. Design → Special Topics
    
13. Design → Cris Moore
    
14. Design → Cris Moore
    
15. Design → Special Topics {Puzzle Tolerances}
    
16. Design → Marc ten Bosch

I waffled on including level names, but omitted them for simplicity. If that choice or any other is making this guide less useful than it could be, please let me know in the comments!