I hope the buyer will be kind enough to share the .nsp after he get the game.
Somewhat amusingly that would probably be the least debatably illegal thing here.
The legality debate as I see it.
As far as I am aware he/his company owns the copyright to the game and can create and distribute copies as he sees fit.
Steam said no thanks to distributing it (somewhat reversing their position on not playing censors/gatekeeper)
https://gbatemp.net/threads/steam-bans-the-sale-of-pick-up-artist-fmv-game-super-seducer-3.585240/ and seemingly Nintendo also said no thanks.
The trouble with Nintendo is largely twofold.
1) Nintendo theoretically want to claim exclusive right to authorise works on their device.
Theoretically this was solved decades ago with both their lawsuit against atari (which may come into play here), Sega vs accolade and maybe Galoob vs Nintendo, as well as why we have not seen any homebrew devs troubled as a general concept despite homebrew being around in big form for years now. Practically there is the DMCA and has things against bypassing encryption which might be tripped up by this depending upon how they do it (said homebrew from the earlier line was often seen to miss headers or not be encrypted and get the end user to do it for a reason).
2) If Nintendo provided some libraries for use in the port then there might be both agreements for the libraries and maybe some distributor agreements saying they get final say.
I don't have whatever they would have had with Nintendo, some did mention the stuff they did on earlier consoles where they opened things up for some lower end developers but rather locked them down,
https://www.unrealengine.com/en-US/faq is probably on the pricer side of things but generally represents the line of thought and words you are likely to encounter.
https://github.com/github/dmca/commit/ada33178ba1e9496453e18e097634a2fefa45e87 from earlier is a similar issue, but rather than just source there is distribution as a thing they might want a taste for.
If it is "we have final say" then that is one thing, if they need a cut and this is not allowed under marketing stunt or something then it might be that Nintendo gets their little cut for this and that is the end of that.
We don't however know what libraries, agreements and whatever else is in place here that might be bothered. We have however seen many cases of stolen code, borrowed code, agreements over distribution and whatever else over the years so people are wondering what might be going on behind the scenes here.
Why do people hate the creator so much? I've never seen people complain so much about a potentially illegal copy of a game before. Especially considering how many people obtain illegal copies of games. It's his game anyway so idk what the fuss is.
Seems to be twofold.
1) NFTs seems to be popular to hate among some. Using them in this then condones their use thus...
2) The guy is a self styled pickup artist (often abbreviated to PUA).
PUA is then often lumped under the manosphere or red pill philosophy (this might take a flow chart/org chart and the players involved would be even more complicated but the big camps would be PUA, men's rights/MRA, men going their own way/mgtow* and various others that draw various elements from all of them) which some find objectionable as a general concept.
*considered something of a bad word for many search engines so code words/older words like bachelor lifestyle, free agent lifestyle and similar things are quite popular nowadays. It is quite a popular field actually but dating advice and motivational speaking tends to be so who knows.
PUA specifically then posits that getting laid is fun and offers tricks and tips on how to do it. Some of it is motivational in nature (rock up with perfectly done hair and abs you could grate cheese on whilst telling some jokes and flashing like you have cash and it does rather make at least a few ladies go weak at the knees that might not otherwise have done so had you turned up as a chubby guy in a ratty tshirt), some of it is passive psychology (what is subconcious defensive posture, what does legs open and stopping moving mean, what does that quick flash of disgust mean...), some of it is more active (see the idea of negging for an oldie but a goldie, but others are stuff like nature of eye contact, posture...). Many PUA then sell courses for others to learn to be just like them which some find distasteful, some consider it a scam (how well it works is up for debate after all), much PUA stuff is all about getting laid and running away afterwards (pump and dump, ejaculate and evacuate, shoot and scoot... for some of the amusing terms) to repeat that again and again which some find distasteful, and others find the active measures distasteful or brushing up what they might deem consent (some have even floated laws on what lying about your job/status might be in this and that is without going into what has seen people fired, blacklisted and kicked out of schools this last however long so who knows). Take your pick on those if you want, though others might have further objections.
Anyway in the grand tradition of many offering training** in the modern world and having heard the word gamification then he made some games about it/attempting to teach it and sought to go about distributing them. Those that find them distasteful either work in the various companies saying yay or nay, are afraid of the stink either those that find them distasteful will kick up, or are afraid of their corporate overlords (see mastercard and patreon and bannings there
https://bitcoinist.com/patreon-mastercard-ban-bitcoin/ , or paypal vs flash carts if you want a more relevant to around here topic
https://gbatemp.net/threads/shoptemp-v1-r-i-p.268719/ ). Banned games do tend to go up in money (
sort of relevant at this point) and here we are with him seeking to capitalise on that via the current shiny tech.
**training related video of basically no relevance but here because it is hilarious