"a hunting painfully hard job" - most definitely! Team work required (multiplayer, or bots), but a rabbit or wild fowl or mussels could be taken out by a lone hunter.
The user experience to invoke:
- fear (night time, going to water hole)
- frustration (an unsuccessful hunt, weapons break)
- excitement (during hunt, escaping threats - wolves, bears)
- satisfaction (during feast, finding mate, child born, new tools)
- pride (tribe in good health, good skills, )
The game objective:
- pass of your genes (until the arrival of horse - a future expansion "Into the Bronze Age")
- survive winters (move south, or stock up)
- alliances and war
Desirables:
- first person only
- adaptive animal populations (based on person/10 km)
- caves
- rivers, lakes
- encroaching ice flow
Events to simulate action:
- Weather
- Season change
- Wolves/Bears
- Other humans
- Food low
- Resource found
- local tribe summer/winter festival
- Injuries (fall, weapon, bite, claw)
I would be happy to be a game designer (mechanics) researcher and tester, but unfortunately I cannot produce game code or produce graphics.