(2007) by Backbone Entertainment. In 2008, Sega Studios USA merged with Sonic Team, making Iizuka the head of Sonic Team and a vice president of product development for Sega. In 2016, Iizuka relocated to Los Angeles to oversee development with the goal of making Sega's studios in Los Angeles "a centralized hub for the global brand". Games Sonic Team has developed a number of video games, with many of them becoming bestsellers. The studio is best known for its Sonic the Hedgehog series of platform games, which account for the majority of Sonic Team's work; the 1991 release of Sonic the Hedgehog is considered one of the most important moments in video game history, as it propelled Genesis sales and displaced Nintendo as the leading video game company. Sonic Team have also developed a wide variety of other games, including action games such as Nights into Dreams, Burning Rangers, and Billy Hatcher and the Giant Egg, the online puzzle game ChuChu Rocket!, the online role-playing game Phantasy Star Online, and the music game Samba de Amigo. Phantasy Star Online is credited for introducing online RPGs to consoles and was the first online RPG for many players. According to Sean Smith of Retro Gamer, few companies could claim to have released as many AAA games over such a long period, especially between 1991 and 2000. Some Sonic Team games, such as the original Sonic games for the Genesis and Nights, are considered some of the best video games ever made. Iizuka has said Sonic Team would be open to developing a third Nights game or a sequel to Knuckles' Chaotix (1995), if Sega were to commission them. Sega and Sonic Team have been frequently criticized for their handling of Sonic the Hedgehog after the beginning of the 3D era of video games. Edwin Evans-Thirlwell of Eurogamer described the 3D Sonic games as "20-odd years of slowly accumulating bullshit", and that unlike Sonic's main competitor, Nintendo's Mario series, Sonic in 3D never had a "transcendental hit". Zolani Stewart of Kotaku argued that Sonic's portrayal starting with Sonic Adventure with the addition of voice acting and a greater focus on plot and character narrative changed Sonic into "a flat, lifeless husk of a character, who spits out slogans and generally has only one personality mode, the radical attitude dude, the sad recycled image of vague '90s cultural concept." Sega of America marketing director