This means that some, shall we say, unsavory products might slip through the cracks here and there, and it seems as though one seller has actually managed to advertise ROM hacks based on Nintendo properties, with one Nintendo 64 game entitled 'Shotgun Mario 64' specifically highlighted online.
In fact, it looks as though none other than Nintendo of America's President, Doug Bowser, has caught wind of the products thanks to a tip via LinkedIn. The original post seems to have been deleted at the time of writing, but screenshots of the tip and Bowser's subsequent reply, in which he simply states "Appreciate the visibility", can be seen below.
Now, this on its own might not seem particularly mind-blowing, but it does admittedly come at a rather curious time. Walmart has recently been highlighted in the news twice for supposedly cancelling pre-orders for Switch releases such as Luigi's Mansion 2 HD and Paper Mario: The Thousand-Year Door,
While there's no direct link between the two stories, it's clear that Walmart has a pretty close relationship with Nintendo when it comes to new game releases, so we'd be interested to see how both firms act upon the sale of Nintendo ROM hacks. Presumably, the products would simply be promptly removed, but at the time of writing, a grey cartridge for 'Shotgun Mario 64' can still be viewed and purchased on the marketplace.