Earlier this week, resourceful Super Mario fans unveiled a PC port of the classic 3D platformer, Super Mario 64. The original game was reverse-engineered and recompiled to run DirectX 12, resulting in a much cleaner, higher-resolution experience than the original. If you just said, "Wow! That sounds like it'd be a mating call for Nintendo's lawyers," you're absolutely right. Nintendo's lawyers and representatives have filed copyright claims, and the Super Mario 64 port is rapidly fading from file-hosting sites.
TorrentFreak obtained one of the complaints, and noted the action was taken, at least in part, by Wildwood Law Group LLC. TorrentFreak notes Wildwood Law Group often works with Nintendo to "suppress the availability of modding tools and products." Indeed, a quick Google search reveals Wildwood Law Group put a stop to a 2019 Kickstarter for Ditto Eevee pins.
Nintendo is infamously litigious on any given day of the week, but it might be feeling especially touchy thanks to the recent source code leaks for the Wii and beta versions of Pokemon Gold and Silver. There are also rumors that Nintendo plans to bring its retro 3D Super Mario games in some form to the Switch later this year. If that's true, there's no doubt Nintendo would regard a freely-distributed upscaled version of Super Mario 64 detrimental to its own Super Mario 64 remaster or remake.
One irate fan in TorrentFreak's comments asks, "What gives Nintendo the right to claim copyright on something they no longer sell or support?" The answer is, well, copyright law. Nintendo absolutely has the legal right to axe fan projects based on its properties—and the company is fanatically protective of Mario. Bad PR invariably follows these takedowns, but Nintendo has proven several times over that it's not concerned about that. Fans seemingly aren't concerned about Nintendo's legal department, either. They make or alter Mario games; Nintendo shuts them down ASAP. The cosmic ballet goes on.