Japanese game company Square Enix acquired Eidos in April 2009, restructuring Eidos into Square Enix Europe. Crystal Dynamics remained the developer of the "Tomb Raider" games. "Lara Croft and the Guardian of Light" introduced co-operative gameplay to the series, a move that brand director Karl Stewart said was meant to "show as a more humanistic character" by placing her in a situation that differed from previous instalments. The game uses the same technology featured in the studio's past "Tomb Raider" games. Despite the changes implemented in the titles, Crystal Dynamics believed that the series required further reinvention to stay relevant.