Ninja Gaiden Sigma

Ninja Gaiden Sigma is a updated rerelease of Ninja Gaiden Black, a game wholly about being killed repeatedly by ninjas.

Revision Differences
Compared to the previous edition, Ninja Gaiden Black, many puzzles were removed, an additional weapon (Dragon's Claw and Tiger's Fang) was added, some enemies were removed (Gobbdecks) and some were added (Mermen) and water running was automated.

Regional differences
In all versions but the American one, beheadings of human enemies have been removed.

Unused Weapon
As seen in early screenshots of the game, Rachel originally had a whip weapon. Some remnants of it can still be found, including a broken attack animation and a model. The Whip can actually be selected by modifying a save file.