Some lingering technical issues, bad dino AI, and an extreme amount of grinding to reach endgame are the main factors keeping it from being as sharp in the tooth as it could be.
ARK: Survival Evolved has plenty of that to go around across its multiple sprawling maps - which it calls ARKs - which can be explored solo or crowded with up to 100 players. Running up a snowy mountain firing a machine gun at a woolly mammoth from the back of a tyrannosaurus is a fantastic example of the reason many video games exist: living out ridiculous childhood fantasies.
