Brinstar Depths (ブリンスタ深部, 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.
This stage is unique, due to it being a 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" are loosely applied). 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. In Ultimate, some of the corners have been made into ledges.
This stage comes from Metroid. The name of this stage could be based on how Kraid is deep below Corridor 1. of Brinstar. Metroid is the first appearance of the mini-boss "Kraid". Kraid is the boss of Brinstar in Super Metroid also. Even though Kraid first appeared in Metroid the design of Kraid in this stage (including his gigantic size) 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 played on this stage comes from Metroid. the song is a mix of two songs. 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. 
- There is a glitch where, if timed just right, Kirby or Jigglypuff can float through the stage.
- Even though lava is at the bottom of the stage, the player will be KO'd before they ever touch it.
- In All-Star mode, this is the only example of a borrowed home stage not using different music. When fighting Ganondorf, the Brinstar Depths music plays as normal.
- It's possible that the organic specimen in the middle of the platform is Mother Brain.