Countdown

Countdowns have long been the signature of the Metroid series (every game except Metroid II: Return of Samus has at least one). Often, after defeating the final boss, Samus must evacuate the location in a certain time. Six minutes is a very frequent time limit, though three minutes and one minute have been known to appear as well. They either have the same (albeit remixed each time) music track, titled Escape!, or Ridley's theme is used. Metroid Prime and Metroid Prime Hunters have had original music tracks though.

To date, Metroid II: Return of Samus is the only game in the series to not feature a Countdown. Instead, Samus leaves Phase 9 with the Baby carving out obstacles for her.

Metroid
In Metroid, upon defeating Mother Brain, Samus is given 999 time units, (3 units is one second, therefore the time limit would be 333 seconds, or about 5 1/2 minutes) to climb up a tall, tower-like room to escape from Tourian's Time Bomb.

No explosions occur in the shaft or Mother Brain's chamber. However, the Lava will turn white and all Cannons will begin to flash.

Super Metroid
Super Metroid has two countdowns, both escaping from locations to be destroyed, one at the beginning of the game and one at the end. In the beginning, Samus must evacuate Ceres Space Colony in less than one minute following her first battle with Ridley. At the end of the game, Samus has three minutes to escape from Zebes as the planet begins to explode after defeating the revived Mother Brain.

On Ceres, Samus will encounter falling debris in one hall. Explosions do not damage her, however if she comes into contact with any, she will assume the flinch position as if she was hurt, but she will not take any damage. This does not happen in any other games. The explosions on Zebes are capable of taking out Space Pirates.

Metroid Fusion


There are three countdowns in Metroid Fusion. The first countdown happens in Sector 3, where Samus must race to the Main Boiler Control room to stop the Biologic Space Laboratories research station from overheating and exploding in six minutes. Later, Samus must Space Jump to the top of a shaft with Metroids floating around her in under one minute. In the final sequence, Samus has three minutes to escape the research station whilst it hurtles toward SR388 while fighting an Omega Metroid. This is the first Countdown ever to have a boss included.

In the first countdown of Sector 3, there are no explosions; the screen simply flashes red constantly. During the Restricted Lab escape, there are explosions. No explosions occur during the propulsion sequence.

Metroid Prime
In Metroid Prime, Samus must escape the Space Pirate frigate Orpheon in seven minutes, before it explodes at the beginning of the game. Some fuel caps will explode during the escape, opening new passages for Samus, and once Samus reaches the Exterior Docking Hangar, the frigate will begin to explode.

Retro Studios stated in an interview that a timed escape was planned for the Impact Crater at the end of the game, but they didn't want to delay the game another month for it.

Metroid: Zero Mission


In Metroid: Zero Mission, after defeating Mother Brain, Samus must escape from Tourian and board her gunship in three to one minute(s), depending on the difficulty, by jumping onto various crumbling platforms, similar to the original Metroid. Later, Samus must evacuate the Space Pirate Mothership under five to three minutes after defeating Ridley Robot.

Unlike in Metroid, explosions do occur in the shaft, but they do not hinder Samus. Once she escapes Tourian, the screen will begin to flash pink rapidly. No explosions occur in the Mothership.

Metroid Prime 2: Echoes
At the final sequence of Metroid Prime 2: Echoes, after taking the last of Dark Aether's energy and defeating the Emperor Ing, Samus must return to Aether whilst Dark Aether crumbles from loss of energy, in 8 minutes. Along the way, Phazon blocks the exit as she battles her evil copy for the third and final time.

No explosions occur at all.

Metroid Prime Hunters: First Hunt
Two of the training exercises in Metroid Prime Hunters: First Hunt include countdowns. Regulator has a very large 10 minute time-limit, while the Morph Ball mode ends at 55 seconds if the player does not collect the last module before then.

Obviously, no explosions happen because the timer is not counting down to an explosion.

Metroid Prime Hunters
In Metroid Prime Hunters, Samus must escape from each planet/station after defeating one of the 2 types of bosses and acquiring an Octolith. The time limit differs for each boss encounter, ranging from 8 minutes, 30 seconds, to 2 minutes. There is no explanation for any of these countdowns. Also, when Samus enters the Fuel Stack for the first time during her second visit to the Vesper Defense Outpost, there is a malfunction with the power generator that threatens to destroy the entire station. Samus must get to the top of the room in one minute and fix the problem by scanning a computer in an alcove. This brings the total countdowns to nine, the most of any Metroid game to date.

No explosions occur during most of the countdowns because the location is not blowing up. As Samus leaves the Stronghold Void, a voice will sound, "Octolith taken." twice. Explosions do occur in the Fuel Stack.

Metroid Prime 3: Corruption
In Metroid Prime 3: Corruption Samus must get to the Control Tower before the Leviathan hits Norion in four minutes. Also, she must activate an escape pod in SkyTown to escape the Spire that is dropping on the Leviathan Seed Shield after she shuts off the pod's engines. Neither countdown actually depicts a timer on-screen, as Aurora Unit 242 tells Samus every minute, unlike the rest of the series.

While not exactly indicated on the HUD, a timer does show when on the spire. After killing all the Space Pirates and opening the repair hatch below the escape pod, if Samus looks at the screen she used to shut down the engines, a countdown can be seen on the screen.

While not exactly a "countdown," there is also a time limit on the boss fight against Meta Ridley in Metroid Prime 3: Corruption; this, however, is measured in meters (representing the distance between Samus and the bottom of a shaft) rather than in actual time. If Samus does not defeat Meta-Ridley before they reach the bottom of the shaft, she will be killed when they hit the bottom.

No explosions happen during any of these events, although there are powerful tremors as the Leviathan approaches.

Metroid: Other M
After the Metroid: Other M credits, the Galactic Federation ultimately plans to destroy the Bottle Ship. Just a few days before they do so, Samus returns to retrieve Adam's helmet. As soon as it is in her grasp, a self-destruct protocol activates, giving her five minutes to get back to her ship. She escapes in her Zero Suit (presumably because she had no time to put her Power Suit back on), utilizing the Paralyzer to defend herself against Super Zebesians as she runs to the gunship. This is the first time the Zero Suit is playable during a Countdown sequence.

Explosions occur multiple times, making popping sounds as they happen randomly. They are similar to Super Metroid in that they are still capable of killing Zebesians, but not harming Samus. However, if Samus comes into contact with the debris and the fire, she will be hurt.

Metroid Prime Pinball
In Metroid Prime Pinball, timers appear during several of the Mini-Games, but are not necessarily counting down to destruction, rather, until the game expires.

Super Smash Bros. Melee
In the Adventure Mode of Super Smash Bros. Melee, the player must escape an exploding Zebes in 40 seconds after fighting Samus. The first time the player succeeds, they earn a Samus's Gunship trophy. If they fail, they lose one stock, but still progress to the Dream Land level. Warning Siren plays in this segment.

Super Smash Bros. Brawl
In Adventure Mode: The Subspace Emissary mode of Super Smash Bros. Brawl, there is a countdown during the escape from the Isle of Ancients. Several Subspace bombs are set to go off, and the characters must escape the facility (at this point there is no countdown; the screen automatically scrolls, killing the player if he/she falls behind). Once the player exits the chamber, the player must defeat Meta Ridley whilst on top of the Falcon Flyer in less than 2 minutes.

Trivia

 * Countdowns are likely inspired by similar escape sequences in the films Alien and Aliens, which gave much inspiration to the Metroid series. The escape sequence of Aliens is also similar to that of Metroid Fusion, where the female protagonist is stranded with no means of escape and a dangerous specimen cornering them, and at the last minute, the gunship flies in to save them. This countdown is also similar to the escape sequence in Alien Resurrection, where the protagonist must escape a research vessel before it crashes into the planet below.
 * The Spire Dock Countdown in Corruption is also similar to the countdown of the original Alien, in that the female protagonist willingly activates a self-destruct mechanism to accomplish an objective and goes to the escape pod, but is forced to make an unexpected detour before escaping.
 * In Fusion, a countdown in the Main Boiler is the only one in the Metroid series where Samus is not evacuating the explosion, but rather trying to prevent it.