Haha, this game is certainly making the rounds. One of my friends got me into it the other night, it's strangely addictive
http://king-hobo.mybrute.com/
As far as I can tell it's incredibly random. A friend has a level one with 120+ hp, another is the same level as mine and has several abilities seemingly gotten at random while I have none. About all I -do- know is that you sometimes take weapons from the brutes you beat.