Here is the full list of all 29 BCE achievements.
Burn an offering in your cave
Get 100 kills with spears
Get 100 kills with your fists
Get 100 kills with clubs
Light 50 fires
Extinguish 50 fires
Take a ride off the waterfall
Obtain a blessed weapon
Play on every map
Get killed by the shark
Get stunned by a rock you threw
Light 10 fires with a thrown spear
Extinguish 10 fires with a thrown spear
Win a game
53,594
Reflect a rock and stun somebody with it
Win a flawless victory
Get a double kill with a club
Get a double kill with a spear
Get 10 Kills in a single game
Club someone who is stunned by a deflected rock
Get crushed by a falling rock
Come back and win a game from a 0-2 lead
Extinguish at least 1 fire per round, then win the game
Win 7 matches in a row
Lose 7 matches in a row
Get clubbed off a cliff
Look at the credits
Get a kill with a rock