If you are a Nintendo 64 collector, a speedrunner, or a digital archaeologist, there is one file that sits at the top of the wish list:
Massive repositories of internal Nintendo data found their way online, including source code for the Nintendo 64 operating system and early master files for flagship games. Deep within these directories, archivists discovered early assets, source code repositories, and uncompiled data directly tied to the mid-1996 development era.
These custom ROMs accurately replicate the exact UI, textures, physics, and limitations of the 1996 prototype. The Dark Side: Fake ROM Downloads
The Kiosk Build used early 2D "cartoon-style" sprites for Power Stars and a different power gauge that evolved from a clock hand to a blue pie piece before becoming the final "sun" meter. Level Geometry: Castle Grounds:
What of the E3 build you want to focus on (e.g., deleted levels, mechanical differences, or the history of the 2020 leaks).
One of the most famous elements associated with this era is the unused enemy (the lava dinosaur).