I just got up to the maze on level 13 of Jill Goes Underground so I looked at the map and marked out the route for myself to avoid having to go through trial and error. Since this forum is so .. quiet .. I thought I'd share the image in case someone else needs it in the future - https://i.imgur.com/9L1TQUr.png

To find the solutions to all the other puzzles like the various switch puzzles or even just info on how to reach secret areas check out the manual that's included under Extras. It's basically a mini-walkthrough and I used it myself to pass a switch puzzle on Level 11 (or something) of Underground.

I got the map of the maze from this website, it's super useful and I use it for all my DOS platformers - http://www.vgmaps.com/Atlas/PC/