I'm new here so feel free to ignore my 2 cents accordingly, but I'll throw them in just the same, I don't see this being a MP game. Also, everything in the world that's released as a game doesn't, just because it's a trend currently, have to be released with an MP component. It's also a fad of late to make everything indie a rogue-like even if that game design element isn't needed in every single game release nor that it even necessarily makes an enjoyable game experience, sometimes it and sometimes it doesn't. This industry has a bad habit of piling on an idea till it's applied too far and wide even in places where it doesn't fit. Same happens with MP.
It's ok, in fact it's more than ok, to have games that are SP. The time and energy of development can then be exclusively about putting in more content for SP.