Billy Vs. SNAKEMAN

Interesting little game we have here. At a first look it might appear as a silly, parodised game based on the world of the Naruto anime, with the occasional popping up of cameos from other sources... but, after some playing you'll notice it isn't so.
The game is turn based, with an allotted number of stamina points that regenerates at dawn, so it's actually a better game for casual players than hardcore ones.
Unlike too many other web rpgs, it starts with a tutorial, giving you a basic rundown of the actions you can take, explaining the statistics, the buttons and the numbers.
After the tutorial, you'll be free to start taking missions, increasing your statistic, and with them your level. You'll buy techniques that give you an edge on battles, and so on... pretty standard web rpg stuff, really.
You can also join or found villages, spar with friends, stalk and attack specific other players (not as easy as it seems) and take part in wars.
I'd add more, but the functions are tweaked fairly often, with new options added on almost a weekly basis, so you should probably just try out.
My personal suggestion is waiting to get to Chunin rank before throwing the game away. It doesn't take too much time, and is where the actual fun begins.