Ninja Gaiden Sigma 2 is an enigma in that it manages to both improve and detract from the original Xbox 360 version. The game offers both new and improved features that address some criticisms of the original, but they come at a curious expense of either not fixing or outright removing features in other areas. Far from the definitive version of the game, Sigma 2 ends up doing little more than tread water rather than genuinely improve upon the original material. B-/A+