A spin-off of the Pokémon series, it was released on November 21, 2003 in Japan, March 22, 2004 in North America and May 14, 2004 in Europe.

Throughout the game, Wes rescues "Shadow Pokémon"—Pokémon who have had their hearts darkened by Team Cipher, an antagonistic organization—via snagging.

North American pre-orders included a bonus disc that allows the player to download the Pokémon Jirachi on the Game Boy Advance titles Pokémon Ruby and Sapphire while Japanese bonus discs featured similar downloads for Celebi and Pikachu.

When a battle starts, the screen switches to a turn-based interface where the player's and enemies' Pokémon fight.

In the single-player battle mode, the player competes at Colosseums—stadiums used throughout the game for Pokémon battles—and earns "Poké Coupons", another currency which can be used to buy rare items.

Team Snagem (スナッチ団, Sunatchi-dan, Snatch Gang), a criminal organization that uses the "Snag machine" technology to capture the Pokémon of Trainers, serves as an antagonistic entity in the game.

(ミラーボ, Mirābo, Mirorbo), the explosively-tempered bodybuilder, Dakim (ダキム, Dakimu), the queen of the Under, Venus (ヴィーナス, Vīnasu), and the strategist of a scientist, Ein (ボルグ, Borugu, Borg).

[11] Wes starts at the Outskirt Stand, a dilapidated train engine in the middle of the desert that has been converted into a shop.

Wes proceeds to Phenac City in time to see two men named Folly and Trudly dragging a sack.

[13] After defeating them in battle, Wes unties the sack to find Rui,[14] a girl who was kidnapped because she saw a black aura on a Pokémon.

The local police force is powerless to stop the practice, so Wes and Rui see Duking, an influential man in Pyrite who runs the Colosseum.

Inside the nearby Pyrite Building, a Cipher Peon is about to present the Shadow Pokémon prize, but another one recognizes Wes.

As Rui introduces Wes to her grandfather Eagun, another villager runs into the room, telling them that the Relic Stone—a shrine protected by Celebi that can purify Shadow Pokémon—is under attack.

After departing from Kids Grid, the residents of The Under claim to have caught a spy, Duking's friend Silva.

Once defeated, Nascour tries to leave, only to be interrupted by Es Cade, who reveals that he is really none other than Evice, the head of Cipher, and battles Wes.

When Wes defeats him, Evice attempts to escape using a helicopter, but the legendary Pokémon Ho-Oh swoops in and blasts it out of the sky.

The North American disc also contains the exclusive Pokémon Jirachi that can be downloaded to the player's copy of Ruby or Sapphire.

The Japanese release contains a downloadable Celebi instead and requires a completed save file of Pokémon Colosseum.

Despite public anticipation the Bonus Disc was not released in PAL territories, prompting Nintendo to issue an official apology.

In Japan, scannable cards for the Nintendo e-Reader were available for purchase that featured additional trainers to battle and capture Shadow Pokémon.

[26][27] Pokémon Colosseum was generally well-received upon release, with respective scores of 73/100 and 73.46% from aggregators Metacritic and GameRankings.

[37] Critics praised Colosseum as the first true 3D role-playing installment in the Pokémon series and for its darker tone.

[36] IGN staff writer Craig Harris said that the adaptation of the Pokémon RPG formula to the 3D zeitgeist "does a decent enough job" and is "a bit more linear and straightforward".

[34] GameSpot reviewer Ryan Davis offered a similar opinion, concluding that "[t]he visual style ... has gone off the deep end".

[10] GamePro writer Star Dingo called the graphics as a whole "insanely cute" but criticized the lack of animations showing two Pokémon attacking in tandem.

[33] GameZone's review took a more positive stance, saying that "[a]nimations are brief but impressive; each attack move is more elaborate and more extravagant on the 'Cube.

[35] Nimensio Rivera of the San Diego Union-Tribune praised the game for its gameplay, graphics and replay value, but criticized its sound, specifically its soundtrack which was described as “Saturday morning-ish.”[39] GameZone compared the overall town design and environments to those of the landmark Final Fantasy VII.

"[36] Harris denounced the game's usage of old Pokémon battle cries, a recurring complaint of the series.

[44][45][46][47] In 2005, the game was certified as part of Nintendo's Player's Choice line in North America, representing at least 250,000 copies sold.

Set in Orre five years after Colosseum, it features a new protagonist snagging Shadow Pokémon from Team Cipher.