I think even if it wasn't trademarked, they'd likely look into Passing Off (or whatever equivalent laws are present in the country they would decide to proceed with legal action is available), given the exact same name and style of a Nintendo product is being used.
There is also copyright in the design and layout of the NES interface, which has obviously been copied (it's the whole point of the project!), there's likely another option there.
There is no “NES interface”. It’s all just code written by each individual dev team, using assets created by their art teams. I don’t really think there’s anything that actually exists that could legally be called “the NES interface” when it comes to design rights
There is also copyright in the design and layout of the NES interface, which has obviously been copied (it's the whole point of the project!), there's likely another option there.