Ninjas do battle with Heroes at retail

The Xbox is heading into its twilight years with the impending release of the Xbox 360, but there's still some life left in the system, as evidenced by today's arrival of Tecmo's Ninja Gaiden Black and Microsoft's Kingdom Under Fire: Heroes in stores.

An updated version of last year's popular action title Ninja Gaiden, Ninja Gaiden Black is the last Team Ninja game for the Xbox before the developer turns its attention to the Xbox 360 and finishes up development of Dead or Alive 4. Ninja Gaiden Black combines the original game with its two Xbox Live Hurricane Packs, a new mission mode, new difficulty levels, and the original Ninja Gaiden arcade game.

Developed by Phantagram's Blue Side Studios, Kingdom Under Fire: Heroes is a prequel to last year's metal-tinged real-time strategy action sleeper hit, Kingdom Under Fire: Crusaders. The game returns players to the continent of Bersia as one of seven heroes from the human alliance or the dark legion. Heroes gives players more than 50 new missions to work through in single-player mode, unlockable characters, new multiplayer modes, and custom campaign features.

Both games are rated M for Mature. Ninja Gaiden Black retails for $29.99, while Kingdom Under Fire: Heroes will run gamers $39.99. GameSpot has already weighed in on Ninja Gaiden Black, and a verdict on Heroes is coming soon.