Ninja Gaiden is an action-adventure game for the original Xbox video game console. Team Ninja developed the game for five years before Tecmo released it in 2004. It has received much critical acclaim, with several publications proclaiming it one of the best and most difficult video games ever made. [citation needed] The game mechanics of Ninja Gaiden have gradually evolved through downloadable contents and two re-releases, Hurricane Packs 1 and 2, Ninja Gaiden Black for the Xbox in 2005,Ninja Gaiden Sigma for the PlayStation 3 in 2007 and Ninja Gaiden Sigma Plus.