Can you tell that I really like Ninja themed games like Adventure Quest? In Ninja Saga you'll get to play a great casual role playing game as a ninja. With over a million players it's also one of the most popular out there, much of this success comes from the cross platform gameplay that has support for Facebook, iOS and Android players.
The story for this game world is quite a standard one and nothing that will keep your attention for long, it's the sort of game that you're playing for the gameplay and interaction rather than a deep and engaging story (this is fairly standard for browser games).
Gameplay is all turn based and pretty focused around missions that are given to your ninja avatar, it's a formula that Adventure Quest originally made popular so you'll feel very much at home in the experience. There is also a good amount of PvP available on the PvP servers fi you want to take your item and skills into battle against someone else.
The graphics are also some of the best in this browser space so the game and animations are always enjoyable to watch. Some of the characters and enemies are fairly generic though which does bring it down a few notches, mini bosses are excluded from this though and are generally quite interesting which does make you look forward to the next one.
If you're interested in spending money to get ahead then you'll find good value for your dollar but at the same time free players won't feel too disadvantaged provided they can invest the extra time needed.