So, a little way to make the game a whole lot more difficult. Probably not much different than what most do already, but here we go...
Rule one: Leave your starting town as soon as you can. Others are evil and foolish. Drop your starting equiptment as soon as you can.
Rule two: Break nature to your whims. Snap wolven legs, beat down tigers, but never kill them. Train yourself in the art of throwing and fighting, and if you ever actualy kill a beast you must take its body and use it the best you can. Respect the mammoth, tribal.
Rule three: Every time you meet one of your own race, you must kill them in the slowest ways imaginable. Other's you must try to avoid as much as you can, and take care not to approch them. Bandits are fair game, however.
Rule four: No weapons are alowed. Those are evil, evil things, not natural to begin with. If nature wanted you to use metal or stone, it would not have given you teeth or nails.
With this, go out and kill things.