Meh. It is a nice, short story, with a slightly interesting storyline which is never fully explored. Once the mystery is uncovered, there is nothing more to the game. It is definitely worth a playthrough, but once the player figures out how to create cycles of material collection, the game offers no further challenge.
Clearly an homage to Ninja Gaiden, though slightly easier. Controls are perfectly responsive and fluid. The mid-game twist made it especially endearing to me. The writing has a clear tongue-in-cheek and "wink, wink" aspect to it which demonstrates self-awareness and the creators' own love of their work. A very enjoyable action game.
