So yeah, I used this when it was in its early days and It was amazing then and still is, but to charge $5. *Sigh*
3DNes in particular and emulators in general are perfectly legal. It doesn't violate any IP of theirs. What do you think about Parallel, VM Ware? They are all emulators after all.
VM Ware and Parallel are used specifically as learning-environmental tools for developers, schools,and engineers so legalities wouldn't be problem, concerning that said person(s)(companies) provide their own .iso.
Emulators should be legal as they are a separate engine. I have seen before though as others Nintendo taking down many of the ROMS featured on emulator sites and sites themselves, though there are still a few hidden that remain.
While it tickles me to see mod development like this (Homebrew,Emulators,etc) issues such as below have happened. Their corp/motto page also takes a firm opposite stand against emulators, roms, etc as snippet here: "
How Come Nintendo Does Not Take Steps Towards Legitimizing Nintendo Emulators?
Emulators developed to play illegally copied Nintendo software promote piracy. That's like asking why doesn't Nintendo legitimize piracy. It doesn't make any business sense. It's that simple and not open to debate."
While many players/fans are supportive of development, often times company is not. Personally, I think this development is great and opens up some nice VR opportunities.