Brinstar Depths is a stage in Super Smash Bros. Melee that can be unlocked by playing 50 battles in Versus Mode. It is also one of Samus's home stages, but the player plays against Ganondorf and his teammates on this stage in All-Star mode.
The stage is a giant meteor that has one platform at the top and one at the bottom. Often Kraid, the giant monster in the background, will rotate the stage. The stage will then be at a different angle when it is rotated. This stage has no ledges no matter how it is rotated. Even if Kraid rotates the stage to how it began, the stage is unlikely to be precisely the same.
Brinstar Depths is banned in both singles and doubles tournaments, primarily due to its low blast line, which strongly favour vertical KO moves versus horizontal. Additionally, the stage lacks edges that can be grabbed, and the stage has a multitude of stalling potentials, due to small platforms ont he stage that can quickly become isolated from the main game. Additionally, depending on the placement of such platforms, caves of life can become a problem.
Metroid is the first appearance of the mini-boss "Kraid". Kraid is the boss of Brinstar in Super Metroid as well. Even though Kraid first appeared in Metroid the design of Kraid in this stage looks like how he appeared in Super Metroid. However, the overall design of this stage's background doesn't look like Kraid's lair in Metroid nor in Super Metroid. Also, the main platform could be trying to give it the "Brinstar" feel to the stage (such as the rocks, the organic growth, etc). 
The song that plays on this stage is a mix of two songs, both of which come from Metroid. The first part is the music that plays in Kraid's lair. The second half is the song that plays when in an item room.