First, the specs: I am using an iTouch 4G running iOS 5.0.1
The good things: Puts a twist on Fruit Ninja. That's it.
The bad things: Sushi Ninja has horrible, 2D graphics that are nowhere near what it is trying to rip off. It's controls are terrible, and gameplay lags horribly, not letting you see what you are doing. Ads frequently pop up, but I am not too worried about that. The blade is thin and awkward, the sushi do not move realistically, the entire thing is just a very bad knockoff if Fruit Ninja.
The bottom line: If you are looking for a free game that is much better and very similar to this one, get it's official counterpart, Fruit Ninja.
Recommended: No.