Frigate Orpheon (フリゲートオルフェオン, Furigēto Orufeon) is a starter stage in Super Smash Bros. Brawl. It is one of three stages that has its roots in the Metroid universe in Brawl, but the first based on a location in the Prime sub-series of the franchise.
Frigate Orpheon's portrayal in SSBB borrows several aspects of the original locale and implements it into the stage. The general design is very reminiscent of the frigate as it appeared in Metroid Prime. As well as that, it sometimes experiences power outages, knocking out the lights and therefore making it more difficult to see the position of the platforms. The Parasite Queen is featured inside the reactor core whilst utilizing the same rotating forcefield it used against Samus in the boss fight with it. However, the Queen is merely there for aesthetic reasons; it has no effect on the proceedings of the brawl.
The main element that has been integrated into Frigate Orpheon is the 180 degree flip. The stage actually has two different arena layouts arranged in a vertical column opposite each other, but players are only brawling on one at a time. Every so often, a loud siren blares out and a bright yellow warning light flashes in the background. This indicates that the stage is about to turn upside down. When this happens, the camera quickly shifts around and the characters fall onto the other layout. The sudden movement can put people in difficult situations depending on their positioning when the flip took place. However, game director Masahiro Sakurai suggested on the Smash Bros. DOJO!! that staying in the air when the alarm is going off will reduce the negative effect that the stage's flipping has on one's character.
The stage layouts are as follows:
 In competitive play
This stage is usually a counterpick and is sometimes banned in tournaments. This is largely due to the flipping of the stage which can cause unintentional self destructs. The ledges are also ungrabbable at times, creating a disadvantage for characters with tether recoveries or other characters who rely on a ledge to recover, such as Link.
The stage's main difference from other starter stages is that the right ledge is ungrabbable at certain times, which creates a large disadvantage for characters that rely on tether recoveries to recover, such as Olimar and Zero Suit Samus, as well as other characters who rely on the ledge to recover, such as Falco. Frigate's moving platforms can also help characters recover should they be lucky enough to land on it, similar to the Support Ghost on Yoshi's Island.
At the beginning of Metroid Prime for the Nintendo GameCube, Samus Aran received a distress signal from a nearby space frigate. She landed on Frigate Orpheon and soon discovered that the vessel had been utilized by Space Pirates to research the deadly substance known as Phazon. While fighting her way through the facility, she also learned that a parasitic virus was growing and rapidly spreading there. Eventually, she found the reactor core and battled with the Parasite Queen. This stage is based off of this room. In Metroid Prime the player would have to try to aim and shoot her while blue energy shields spun around her. Those blue energy shields can be seen in this stage. After defeating the creature, the reactor reached critical meltdown status and Samus was given just seven minutes to flee the vessel. She managed to escape to her own ship and shortly afterwards, Frigate Orpheon crashed into the planet Tallon IV. For the purposes of the game, this area effectively acted as the tutorial of the controls for players. Later on in the adventure, Samus encounters the remains of the frigate and must fight her way through them in order to gain access to the Phazon Mines.