Ancestors: The Humankind Odyssey is on sale for ~$5 at the moment, so I finally bought a legal copy.
Ancestors is notorious for being as obtuse as a game can possibly be, but once you DO understand how the game works it's also insultingly easy to win.
In fact, because of how the game's progression works and because it's so easy, I've never been able to see probably the last 25% of the "upgrades" you can get. I've never so much as seen the 3rd biome, the African Plains, where you're supposed to end the game.
This is because I play efficiently, cranking out kids to get genetic mutations as fast as possible and lock in as many Neuronal Upgrades as possible in every generation. Playing well makes you evolve "faster than history", which will end your game prematurely, because the game MUST end the equivalent of 2,000,000 years before modern man evolves.
If I ever want to see my monkeys moving in packs, walking permanently upright, fighting with weapons, and able to digest meat and eggs, I'm going to have to do an anti-optimal playthrough where I evolve as inefficiently as possible, and throw all my monkeys off cliffs like Dragon's Dogma pawns so that their deaths negatively affect my evolution speed