Ultimate Play The Game (often shortened to Ultimate) was a video game developer in the 1980s. Ultimate released a series of successful games for the Sinclair ZX Spectrum, Amstrad CPC, BBC Micro, MSX and Commodore 64 computers from 1983 until its closure in 1988. Ultimate are perhaps best remembered for the big-selling titles Jetpac and Sabre Wulf, each of which sold over 300,000 copies in 1983 and 1984 respectively, and their groundbreaking series of isometric arcade adventures utilising a technique termed Filmation. Knight Lore, the first of the Filmation games, has been retrospectively described in the press as "seminal ... revolutionary". By the time of the label's last use in 1988 on a retrospective compilation, Ultimate had evolved into Rare, and moved on to developing titles for Nintendo consoles. Rare was purchased by Microsoft in 2002 for US$377 million, a record price for a video game developer, and now develops exclusively for Microsoft's Xbox One console. In 2006, Rare revived the "Ultimate Play The Game" name for an Xbox Live Arcade remake of Jetpac named Jetpac Refuelled.