After the merger of Sega and Sammy into Sega-Sammy Holdings, a number of restructurings took place. Among these was the closing of United Game Artists, and the folding of its staff into Sonic Team. UGA head Tetsuya Mizuguchi, who was the leading designer of titles such as Rez and Space Channel 5, cited the changing company culture as a reason for leaving to form an indie developer.
In 2004, Q Entertainment debuted their first title: Lumines. The PSP game is one of the best-regarded titles on the platform and has spawned an entire franchise. A PSP sequel was created in 2006 alongside an Xbox Live Arcade release of the game. In 2007, Lumines and Lumines II were ported to the PlayStation 2 in the form of Lumines Plus. The game also became available on PC at that time and was released on Steam in 2008. Another non-physical release of the game happened in 2008 when Lumines Supernova was released on PlayStation 3 via the PlayStation Network. The latest release of the game is an iPhone version named Lumines: Touch Fusion. The iPhone game was released in 2009. The game has seen a release on every current generation platform except for the Nintendo DS.
Another Q Entertainment franchise, Meteos, originally debuted on the Nintendo DS in 2005. A Disney version of the game was released in 2007 and the game was later adapted for the home console market in the form of Meteos Wars, a 2008 release.
In 2006, Q Entertainment released Every Extend Extra for the PSP. The game is based on the PC game Every Extend, which was supposedly brought to the attention of studio head Tetsuya Mizuguchi after an employee skipped work to play it. The Q Entertainment title adds a more percussive, electronic soundtrack as well as flashier, more vibrant graphics. The game was re-made for the Xbox Live Arcade in 2007 and was released as Every Extend Extra Extreme.
Q Entertainment worked with Phantagram on the 2006 Xbox 360 game Ninety-Nine Nights. They also developed Gunpey for DS and PSP, another 2006 game.
In 2008, Mizuguchi's classic Rez was ported to the Xbox 360 (via the Xbox Live Arcade) in the form of Rez HD. As the title suggests, it is a high-definition update of the game. It also features 5.1 surround sound and online leaderboards, as well as various audio-visual options not available in other releases of the game.
Q Entertainment also handled the 2009 DS release of Peggle.
At the E3 2010 Ubisoft press conference, Q Entertainment announced Child of Eden, a spiritual successor to Rez. Mizuguchi demonstrated the gameplay using Microsoft's Kinect controller. It is undetermined whether or not the game will support Sony's Move controller as well as if the game will be a digital or physical release.
In 2013 Tetsuya Mizuguchi left Q Entertainment and went on to form Enhance Games.