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 single, giant irregular stone (with one continuous "floor") with two floating smaller companion stones at the top and bottom of the stage (though the terms "top" and "bottom" loosely apply on this stage). The lava at the bottom of the screen is merely graphical (unlike Brinstar's acid) and functions only as a blast line. Often Kraid, the giant monster in the background, will rotate the stage in either direction, moving the whole rock for only a few seconds at a time. However, no limit is set regarding to what extent it may be rotated in total, meaning it can flip upside down. Even if Kraid rotates the stage to how it began, its position is unlikely to be precisely the same, due to the fact that the rotations are slightly randomised in duration. Also of note is that the nature of the stage's continuous floor dictates an absence of ledges entirely, though wall-grapples remain effectual.
 Tournament Status
Brinstar Depths is banned in both singles and doubles tournaments, primarily due to its low blast line, which strongly favours 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 on the 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 track that plays on this stage is a mix of two compositions, both of which come from Metroid. The first part is the music that plays in Kraid's lair. The second half is the track that plays when in an item room.