Story=ninja's except it's not terrible and chilidish and isn't afraid to have people die. Enough said.
I really liked the style of animation this show incorperates. If you pay attention to the backgrounds you'll understand what I mean, some look like still frames of painting, very pretty. Besides that The animtion looks really good and so does the combat, no crappy suspended pictures, the fights actually look like fights and not still shots of special moves.
I really really like the intro and outro. The music for the credits was mighty. I watched this in english (on netflix) therefore my expectations were low for the english voices but they were all at least satisfactory, a few felt off but they actually picked a solid cast. Sounds aren't off either.
Characters are given depth early and then sort of left alone later. This isn't a huge deal because the characters are still consistant with what we as viewers learn about them however, they did a solid job introducing us to each character and gave some deep insight when the situation called for it. Better than most but still lacking.
I was very surprised at exactly how good this anime was because it was actually really good! Story never faltered and continued on track. Animation was always always enjoyable to look at. Sound and music matched the anime very well. Characters were fairly 3D and were capable of thought/change/growth. Plus the action was great. This anime is bringing back credibility to anime's with ninja!