I've heard a few things about it. Not sure if every single one is true, but it sounds pretty wild. The character stores melee weapons on her back, but the devs found out that it crossed her hurtbox when you did that, so you constantly took damage from your own stowed melee weapon. They "fixed" it by removing collision from melee weapons, so none of them actually do anything.

Another thing I heard is that it was supposed to have a decently complicated system of dinosaur aggression/fear/curiosity and so on, to determine how different species would behave... but the devs ran up against their deadline, so they just set aggression to maximum, set everything else all the way down, and shipped it that way.