I'm going to list the different aspects of this just because it's easier to make sense of.

1. Everyone will play a nation that's sentient, made up non-human species.
2. Technology will be roughly iron age, although it can vary nation to nation.
3. This is not fantasy, but you're allowed to make your species as unique and creative as you want as long as it does not blatantly break the laws of science. (e.i a three ton creature flying) 
4. Humans do not and never have existed.

I think I covered everything there. So is anyone interested, or have any questions?