The problem with that idea is that this game is perfect. There is no way to expand it without forcing it. Adding anything else would just bloat it, take more than it would add. Case in point, in the year and a half since it came out there have been TONS of games 'inspired' by this game posted on itch, new features, new graphics, new gimics, and they ALL are lesser versions of the original.
I agree this masterpiece should have been monetized , even just with ads, but that ship has sailed.