Blasting Bullet Factory

Blasting Bullet Factory is a cut level that has been believed to be replaced by Tick Tock Clock, as it shares multiple elements from that level. despite this, players have reported that they have encountered the painting to the course instead of Tick Tock Clock's clock face. This level also contains a secret portal to a level called "Mario Riding Through The Slippery Slide" which appears to be an early Yellow Cap Switch level.

Geography
This course is very similar to Tick Tock Clock, with several reused assets appearing in Blasting Bullet Factory. It starts on a platform surrounded by lava, with 4 paths to the left, right, front, and back of the platform, with a hallway connecting all the paths in a circle shape, making the map similar to a gear. The back path leads to an area called the Sulfur Conveyor, covered with poisonous gas from Hazy Maze Cave. The course's map spins at seemingly random intervals. In the main room there is a switch, which must be pressed to reveal a long pillar-like area, similar to Tick Tock Clock. In the upper area, there is a small room known as The Manager's Office. The map is inhabited by Heave-Hos, Bob-ombs, Amps, Bullies and Bullet Bills, along with a Motos as a boss.

Missions

 * 1) MEDDLE WITH MOTOS
 * 2) BREAK INTO THE MANAGER'S OFFICE
 * 3) RUN ON THE SULFUR CONVEYOR
 * 4) BULLET BILL'S POWER STAR (Yet to be collected by a player)
 * 5) UNKNOWN
 * 6) EIGHT MINTED RED COINS
 * 7) 100 Coin Star (Presumably)

Meddle With Motos
In this mission, the player must platform up the main room to the upper part of the course. At the top, a Motos will be there. It functions the same as the regular Motos enemy, but counts as a boss. It must be thrown off of the platform 3 times to be defeated. When defeated, it will explode into a star.

Break Into The Manager's Office
At the upper part of the course, there is a window that Mario must jump into. It will lead into an area known as the Manager's Office. There, a star will be present.

Run On The Sulfur Conveyor
In this mission, the player must run to the back path of the main room, where the poisonous gas from Hazy Maze Cave will be present. Mario must run through the conveyor, stopping on platforms to restore health. At the end of the conveyor, a star will be present.

Bullet Bill's Power Star
It is currently unknown how to collect this mission's star.

Eight Red Minted Coins
Like in other courses, Mario must collect eight red coins to spawn a Power Star. The locations are seemingly random.

Mario Riding Through The Slippery Slide
Mario Riding Through The Slippery Slide is a hidden level accessed by pressing a hidden switch found in the Manager's Office to open a door somewhere in the level. It is a longer and more difficult version of the Tall, Tall Mountain slide that must be traversed using koopa shells. At the end, the Yellow Cap Switch can appear, though it is already pressed, likely due to yellow boxes already present in the game. There is a star at the end, as well as a red coin star.

Theorizing
This level looks very finished, so it was probably cut late into development. The likely reason that Blasting Bullet Factory was cut from Super Mario 64 was because of it's difficulty. There is a possibility this is the unused Motos Factory level, seeing as it contains a Motos as a boss and is a factory.

This level might have been originally meant to be a second lava level, like an analogue to Lethal Lava Land (similarly to CCM and TTM, WMOtR and RR, JRB and DDD) considering its painting also uses the same painting frame texture as Lethal Lava Land and it has lava throughout the level.