Let's say I want to publish a NES game and I've written the game and it's in .nes ROM format (I haven't, but let's pretend hypothetically). And I want this software to run on modern platforms like iOS / macOS / Android / Nintendo Switch / Steam / Playstation / etc. So I write a wrapper app/virtual machine/emulator (pick the term you like) that serves to run the ROM and also enable some networked multiplayer functionality and so forth.
Will Nintendo most likely litigate because I used their proprietary (albeit retro/dated/discontinued) format?
And if legal issues are likely to crop up, is it best to (A) contact Nintendo directly to work out some sort of licensing deal or (B) just make some other 8-bit format that is very similar to (but just different enough from) the NES format?
From a retro gaming purist standpoint, certainly the look/sound/feel of the original NES format would be preferred over a format designed to recreate or approximate it.
I understand that when I phrase a question as "will... most likely...?" it invites opinion-based answers. But even opinion-based answers would be appreciated because this question is based on a hypothetical scenario that has not happened. If someone could answer, for example: "You're screwed because Nintendo can sue you based on x premise." or "You can probably do this safely because of yada-yada clause in blah-blah law..." that would still be helpful and I would accept it as an answer.
Note: There is a question similar to mine, and the answer is essentially "they'll probably sue you if you're making money from it". But I'm not really satisfied with that, so I'm forming a slightly more detailed and more comprehensive question.
It is possible Nintendo has released some kind of official statement (and possibly even a licensing program) regarding this matter that I am just not aware of. In that case a link to this in the answer would be appreciated.
Also, should we take into consideration that if the game is published for Nintendo's current console (Switch), that Nintendo would stand to gain some profit from the release anyway and be less likely to complain about the intricacies of what technologies were utilized in the game's creation?
Furthermore, modern games are usually made with a game engine such as Unreal Engine or Unity, and a license fee is usually owed to the creators of the engine by the game developers. The .nes format is not exactly the product of a game engine, but more like the product of low-level machine code. Sure, there are authoring tools like NESmaker that might sort of fall under the category of "game engine"... not really sure. And when you consider how low-level the coding for the NES is, it's not even clear to what extent the ownership of that technology can really be attributed to Nintendo. It may be the case that any .nes file I create is entirely mine, in the same way that any .psd file I make using Photoshop belongs to me (not Adobe). But this kind of software law stuff is obviously not my area of expertise, which is why I am asking here.
Finally, would releasing the .nes file for free possibly lessen the likelihood of becoming a target for litigation based on the premise that anyone can "steal" my game and run it on an emulator, but what customers are paying for with the app is essentially the convenience of running that file on their hardware of choice?
This is mostly a question out of curiosity, but as someone who appreciates retro games and is considering dabbling in game dev, I would like to know. Thanks.
Edit: Come to think of it, there are titles such as Namco Museum being released on Switch and obviously were originally written for NES, so wrapping NES games for a modern console is a current practice. Whether Namco had to pay anything extra to Nintendo to release this title is anyone's guess. It is also possible in Namco's case that they had some existing license deal established from when they first released the games decades ago.
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