At this point making a vanilla game of any sort for money is mostly a waste of time, the market is just over saturated with people thinking they'll get rich quick and with the money vs effort it takes might as well get a real job. I think last year something like 8000 1-year-old regular games didn't even make their $100 listing fee back on Steam, so even vanilla porn and the restrictions that go with that is probably even worse (even if it passes Steam censors it still won't show up for sale in most countries where they can't legally sell it without asking for ID or where all porn is outright illegal).
At this point making your own damned site and payment system along with an AVN/game that has all the taboos people are actually willing to pay for with far less competition is the way to go. Of course this raises the entry fee more to small studio, not solo developer with just a bunch of time and a laptop (ie business loan like any other business if you are not at least well off to begin with). I mean even the illegal stuff does ok as it's still a multibillion $ industry (look how much Silk Road made in just 2 years, $5B, and that was just one guy, though selling all sorts of black market digital goods from other devs), if one is willing to do that and there's demand for it (that will always exist, illegal or not, as a whole all outlawing it does is raise prices, more risk = more reward).
