The only parts of a patent with any legal weight are the dates and claims. (The description is there mostly to help interpret the intent of the claims.) Here's the key claim of application
US20140349751:
Patrick J. Link of Nintendo wrote:
17. A method of adapting an emulator, the method comprising: executing, on a processor, an emulator capable of running a plurality different binary applications; recognizing, by the processor, an identity of a binary application based on an inspection of the binary application; automatically adapting, by the processor, a behavior of the emulator to the binary application based on the recognized identity of the binary application; and generating, by the processor, an audio visual presentation using the adapted behavior of the emulator.
So the patent covers automatic enabling of speed/accuracy tradeoff options in an emulator based on a ROM's hash. Nintendo has been kicking this one around in the USPTO for a long time. Fortunately, the Game Boy is a fairly simple system, and emulators should be able to run every official game (other than perhaps
Prehistorik Man) without hacks. Any emulator that can run homebrew should be immune to the patent.
The other part of a patent is the dates, which determine when the patent expires. Patents filed in 1996 or later expire 20 years after the priority date, which in the case of this patent appears to be 2000 or so. I don't see how this patent is going to have a usefully long term.
EDIT: Added the actual application number