That makes sense, thanks! I have plans to add a "reset" button that would restore the original code, but that work isn't done yet. If you don't mind potential spoilers, you can just search for the puzzle name in this file to see the original comments: https://github.com/jaredkrinke/sic1/blob/master/sic1/shared/puzzles.ts
As far as downloading, right now itch.io is the only option. If you use Steam on Windows, SIC-1 is releasing there (also for free) on Friday (with cloud saves). I don't have any other release plans. For the record, GitHub only has the source code and there are compilation steps required, so that unfortunately won't work for playing, in general.