The Nintendo 64 is a beast to emulate because it’s essentially the Frankenstein’s monster of gaming consoles, built with hardware that seems to have been designed more to confuse engineers than to run games. Its custom Reality Co-Processor (RCP), which handles both graphics and audio, is an enigma wrapped in a silicon mystery. The RCP’s architecture is unconventional, with quirks like pixel-accurate rendering and obscure microcode that developers could modify to squeeze out performance. This means every game is practically its own special snowflake, requiring emulators to juggle endless tweaks just to make Mario’s mustache look right in Super Mario 64. Throw in the N64’s unique use of a 64-bit CPU paired with some clever, if weird, memory management tricks, and you’ve got an emulator developer’s worst nightmare.

Then there’s the controller. Oh, that iconic trident of confusion. Emulating its analog stick—an early adopter of 360-degree movement—is tricky enough, but then you have to account for the fact that developers used it in wildly different ways. Some games, like GoldenEye 007, were built around its unique button layout, making it tough to map cleanly to modern controllers. Plus, the N64’s cartridge-based games could bypass normal hardware constraints, doing bizarre and creative things that push the limits of emulators. Combine all this with the need for high-performance hardware to mimic the N64’s quirks at full speed, and you’ve got a console that still keeps emulator developers burning the midnight oil decades later.