In the early game, winter cold should kill Sapiens (especially the most frail, like old - also children, but that would not be good for a game xD).
After they develop clothes, these deaths would eventually disappear.
The life expectancy should perhaps increase with the progress in the game. (with domestication, Sapiens stop dying from hunting dangerous animals. With clothes, they stop dying from cold)
Winter. Will there also be small ice ages or dry seasons that make life difficult?
When it comes to the subject of death, how is it planned will a kind of death cult develop with graves or monuments?
I know that seasons are planned and they will effect the environment/sapiens as you would expect. And as for death, it exists and graves 'n such are probably planned. However as for death cults, that is probably too dark for the game, however Dave has mentioned religion in the past.