Ninja Gaiden is an action-adventure game developed by Team Ninja for Xbox, released by Tecmo in 2004. Players control Ryu Hayabusa, a master ninja, in his quest to recover a stolen sword and avenge the slaughter of his clan. It was inspired by Tecmo's Ninja Gaiden series, and is set in the same continuity as Team Ninja's Dead or Alive fighting games. Tecmo announced at E3 2005 that Team Ninja was working on Ninja Gaiden Black, and later exhibited a working version of the game at the TGS 2005. Black is a reworked compilation of the original Ninja Gaiden and the two Hurricane Packs. The game features new foes, such as exploding bats and doppelgänger fiends who can imitate Ryu. It contains more costumes than the original, and swaps Ninja Gaiden's unlockable NES games for an arcade version. One key feature of this version is its two new difficulty settings—the easy Ninja Dog and the very hard Master Ninja. Itagaki added Ninja Dog after receiving complaints of Ninja Gaiden being too hard in its default incarnation, although he believed that, with persistence, any player was capable of completing the game.