Marionova64

Marionova64, or MN64, is a youtuber who documents beta SM64 areas and stages. There are 10 documentary videos so far in total.

iQue - Super Mario 64
While not really being this type of video, this video shows the trailer to the iQue port of SM64.

Weird Glitch in Super Mario 64 Discovered
This video seems to show what's supposed to be a glitched version of WMOTR or the Wing Cap course, with a Bowser level feeling to the course.

Inside Bowser's Painting Glitch
This video shows MN64 entering the Bowser painting at the top of the Endless Stairs, revealing the course to be 15 CRSE.

Internal Castle Plexus
A tape found by him and Greenio, showing the ICP.

Breaking the Barrier
The video shows Marionova BLJ-ing into the barrier behind the trapdoor leading to BITDW. He then goes inside another trapdoor which leads to Bowser's Domain.

The room has supposed beta paintings of courses with doors below and a sign warning the player not to go through the door at the top of the stairs. more coming