I was going to post what I knew about the Xingu afterlife, but haven't been able to find a word about it outside of a book I've had since childhood. So I've gotta piggyback on the question adn ask if anyone can corroborate this.

The people of the Xingu river held a belief in the hero Aravatura, who sailed up the Amazon to find the life after death. There he found the spirits of his dead friends, all fighting an army of birds in a never ending battle. When one of the spirits was defeated, a great eagle would devour them and that would be their final death. Aravatura returned to his people ill from the stench of the spirits until he was cured of it by the medicine man.

So if I got that right, then when you die you go to fight birds until you collapse then you're eaten by an eagle. Pretty shitty.

Source:A book called Goddesses, Heroes and Shamans.

I think there's a definitional problem. Without a notion of reward, can you say a religion has a notion of punishment? Wouldn't an afterlife simply be? It might not be pleasant, but 'damnation' implies a judgment and punishment, and if everyone's going the same way, they're not being judged, nor punished, merely shuffled on to the next state of being.