This OVA is based on the original Ninja Gaiden video game that got released on the NES ( 8-bit Nintendo console ) back in the early 90's and later spawned a trilogy, not to be confused by the new Ninja Gaiden games that has been released on the latest Xbox and PS3 console.
The story itself isn't really based on the game itself but used as a background, where the first games main enemy "Jaquio" is mentioned. Besides that the story mainly focuses on human Genetic experiments and you see Ryu mostly fighting enhanced lab animals and some double bladed masked characters that are somewhat reminiscent of the dog like creatures from the game itself.
Considering i saw this for the first time in 2007, i must say it still quite holds up well although i am rather new to the anime community. Its very pacey which is one of the trademarks of the game itself and has a somewhat dark atmosphere and some solid fun in the 45 minutes it takes.
Its definitely worth a watch if you're into anime and video games, since the Ninja Gaiden series were one of the biggest NES games, and was the first game to include cinematic dialogue between the levels.
Off-topic: Personally i wouldn't recommend the game for its game-play, since its among one of the hardest games ever to a point where its very unforgiving and frustrating, but the controls seems pretty solid to make u somewhat forgive these flaws to a point, but the thing that makes me remember the series for is its amazing soundtrack, which till today is still ranks among the best game soundtracks ever, and all 3 games on the NES boasts with classical upbeat melancholic tunes which among with the Mega Man and the Castlevania series is the best music u can get in the NES library. I highly recommend the music from the games to any1 who is a fan of gaming soundtracks.
