Super Mario 64/July 29th 1995 build

The July 29th, 1995 build of Super Mario 64, also known as the 1995/07/29 build, is an anomalous and mysterious build. It dates back to before the Ultra 64 (the initial name for the Nintendo 64) was patented, making it perhaps the oldest piece of Nintendo 64 history.

Because of the sensitive nature of the build's contents, research on the 1995/07/29 build of Super Mario 64 is highly discouraged. It is on the infamous iceberg discussing Super Mario 64's anomalies.

Speculation
It is possible that the 1995/07/29 build wasn't even related to Mario or created by Nintendo. Instead, it was created by an unknown Japanese organization that produced the technology responsible for Super Mario 64's ability to personalize itself to its player's likeness. This build would then be sold to Nintendo and reworked into Super Mario 64.

This build allegedly has an intense texture bug, which causes the textures to change colors rapidly and induce seizures within playtesters. It's rumored these playtesters would experience horrific and nightmarish hallucinations, which seem to be the origins of some of Super Mario 64's most horrific anomalies.

Reportings

 * Everything in this section should be taken with a grain of salt. These are all unverified claims.

Developer Anecdote
An anonymous user wrote of their experience talking to a foreign friend from Japan back in 1995. Their friend used to work at Nintendo, and he remarks of his time working there and working on the very first build of Super Mario 64.

The former programmer and his team were handed the prototype after Nintendo bought it from another Japanese company. The team was tasked with cleaning up the prototype for the Ultra 64. The programmer explains how this build bore no resemblance to the happy-go-lucky Mario franchise, and instead was a rather desolate build. He doesn't recall the appearance of the player character, but refers to them as looking instead "simplistic, like a low-poly ordinary man."

He goes onto discuss the castle itself. Unlike the retail release, the castle was made into one full map meaning that all the castle was smaller to fit into the exterior of the castle. Remnants of this are seen within the demos of the game seen within game shows, where the rooms with paintings are a lot smaller than they are in the release of the game.

The programmer goes into great detail in the basement. The basement was a lot darker in this build and had rather advanced fog for Nintendo 64 standards. According to the programmer, the basement acted as a testing ground for an experimental artificial intelligence that would track the player's "cognitive desires" and subvert them. With this, the basement would usually span endlessly like a labyrinth. One playtester, whom the team neglected to check on before leaving the office for the night, was still playing the game in a delirious and crazed state. He was taken to the hospital shortly after being found, and later playtesters were urged not to enter the basement.

When asked about the upper floors, the programmer said that there wasn't much interesting up there; it was a boring and thin spiral staircase that led up to what seems to be a bedroom. He was surprised to hear about a supposed fourth floor and says that "considering Nintendo made the castle bigger with the use of sub-areas, it wouldn't be surprising that they would try to add yet another floor."

Uncle Anecdote
A throwaway account by the name of 1995SMB2276 commented on this page explaining how their uncle used to work at Nintendo, and was around in Japan at the time of the 1995 build's playtesting phase. His first post reads as follows:


 * "Back in 1995 my uncle was an intern at Nintendo and was often tasked with odd jobs that varied from errand running, transcribing, organizing, etc. I heard about the 1995/07/29 build and related phenomena (the Wario apparition, the Bowser room, and so on) a week ago and decided to ask what he knew about it; given that he was living in Japan at the time and doing work at Nintendo, I figured it was worth a try.


 * As it turns out, he was tasked with recording playability, functionality, bugs, etc. found in playtesting. He’s said he’s willing to share the info, and will attempt to translate it back to English (but may have trouble as he’s been out of practice for 17~ years and was never very fluent to begin with), as long as I keep all of his and the playtesters personal info/identifiers secure; it’s a risky move but he’s as interested in piecing the mystery together as I am. Unfortunately, he doesn’t own any other kind of documentation and never knew anything about the company the game belonged to prior so nothing else can be contributed. Given that this was an unpaid overseas internship at an insanely small branch which was closed soon after the matter, it’s unlikely this can get him into much trouble if we’re careful about it.


 * I’ll either reply to myself or make a new comment here when I can provide everything. I’ll be on the same account (throwaway for this topic so I can maintain anonymity + proof that I’m the same person when I give updates)."

After his first post, he would upload four images: the first was a screenshot of an email between him and his uncle, and the other three are the scans that came with that email.