Actually Birth By Sleep is a prequel to KH1 which takes place 10 years before the events of the first game. As seen in a trailer above which was first shown as a secret ending in Kingdom Hearts II: Final Mix you get to play as 3 characters each with their own storylines. Terra (guy with glowing eyes) , Ven (roxas look-a-like) and Aqua (blue haired girl). The game was officially announced alongside Kingdom Hearts:358/2 Days for the Nintendo DS and will both tie in to the eventual Kingdom Hearts III. Recent Nomura interviews speculate that the game will see a eventual re-release of a Final Mix version as Nomura has recently hinted at one for Days. As of now voice work for the game is being done and is due for a release before the Holiday season but don't place your bets just yet as Days was delayed a few times too. There is currently not a release date for the game in the United States but Nomura's plans and the popularity of the series will surely bring it state side.