For fun, I tried to estimate how much money the Steam release made.
One common method of roughly estimating a Steam game's sales is its number of reviews. Gamalytics says the median ratio is 35 sales per review. That number is well reached, but they only tested it against known sales data for non-porn games, and they generally don't consider NSFW games in their methodology at all. I believe the ratio is higher for porn games - you can buy games anonymously on Steam, but you can't review them anonymously, which makes buyers significantly less likely to review.
I've observed ~5 sales-count celebration posts across 3 Mango Party games (where they say like "X game has reached over 80k sales!") and compared with the number of reviews the game had at the time that the post was made. Unless there's something I'm missing, such as if Mango Party numbers include sales from other platforms - but I believe they sell exclusively on Steam - then those three Mango Party games have 197 sales per review, on average.
Steam currently shows Black Souls at 857 reviews. Multiplying by the mentioned sales-per-review number from Mango Party games yields an estimate of 168829 sales. Using the launch price of $12.59, that sales number would be grossing over 2 million USD in sales ($2,125,557) in the first 1-2 days.
In reality, Steam has regional pricing and Black Souls has big communities in countries with weaker currencies. Using this sales number with the cheapest currency (Russian rubles) it's still almost 1 million USD grossed.
Just a very rough estimate of course, and might be super off if any of my steps had a critical flaw. And actually, I suspect using Mango Party's sales-per-review number - even if it were to be a genuinely accurate median ratio for adult games in general - might be a high overestimate for Black Souls, because the community is particularly passionate, so I imagine BS fans are more willing than most porn gamers to drop a review after buying. And of course this is revenue, not profit - it's before Valve's cut, before Otaku Plan's cut, before government(s) cut.
Anyway, definitely a successful Steam release. Congratulations to Toro!