I was messing with Wheel of Fortune for the Nintendo a few days ago, and after looking through the rom in a Hex editor, I was changing simple stuff about the game. As I dug further, it may seem that in order to full edit the game's puzzles, I would have to disassemble and recompile the code to get it to be fully customized.
Hello, Doffo! Welcome to Romhacking.net!
Your post really interested me because you mentioned that you've been messing around with Wheel of Fortune for NES.
Back in late 2010, I started to look through the ROM of the PRG0 version myself and began to document as much as I could find out about the game, intending to eventually make a Wheel of Fortune hack with new puzzles and perhaps a new atmosphere. I was always leaning towards creating a Halloween-themed hack for it, but when it came to creative puzzles, I never really came up with much. All these years later, I never bothered to go back to the game overall.
I documented quite a few RAM addresses and ROM addresses, including palettes, text strings, contestant names, some bits of code, and all of the pointers and actual strings for the categories and actual puzzles.
Depending on whether you're using the PRG0 or PRG1 version, the offsets for a lot of the data groups (if not all of them) are different.
I did successfully change quite a few puzzles while working on an attempted puzzle hack, but I just never continued working on it between breaks and other ROM hacking projects.
From my personal experience working with this game, you would really only have to keep track of the new pointers for the puzzles as you change them (either making them shorter or longer) and keep track of the starting offsets for all of your puzzles.
Unless a part of your plan is to actually make the puzzle display in the game larger to allow the potential for even longer puzzles than current limitations permit, I don't believe that you would necessarily have to worry about digging too much into the game's code for anything major.
Perhaps this isn't necessarily the best place to discuss the subject in further detail (I'm not intending to derail the Introduction Topic more than I probably already have; perhaps a thread can be started in the Newcomer's Board or ROM Hacking Discussion instead) but I'm curious as to what you have already discovered and changed on your own so far, if you would like to share.