Good game, the story is interesting and the difficult is great, the attack animations are super cool and the way the levels are designed makes you feel like a ninja going on a secret mission.
On the downside I miss having a background music and an option to restart the level immediatly after losing. Also I couldn't find any use for the rolling mechanic, at first I thought it could be used to dodge attacks, but then I realized that you must dodge by jumping on the right moment.