It's an Early Access game, issues are expected it's not going to be a finished product. It isn't even at beta stage as it's in ongoing development.
To those saying "Game is nothing like the trailer" what about it exactly is nothing like the trailer? Cause this sure does look like what was advertised.
Sure the visuals may not be the same and they can improve over time as more assets are made. And yes you can post a clip of one thing in trailer and compare it with something totally unrelated in the game to show how ridiculous it is. But does that actually prove it's missing that feature in the game? No!
I mean you get this right next to "Add to cart" option on steam. "If you are not excited to play this game in its current state, then you should wait". It can't be more clear than that. And the state Ark is in right now does not tell me where this game will be in 2 years time, if that was the case then I'd have never given so many developers a 2nd chance after developing dumpster fires. Which is why I think developers deserve a little bit more time & respect than shitting of this kind. No one forced you to pay for it, and nothing's stopping you from refunding the game.
EDIT: That video above that someone posted comparing trailer to the game would have me believe the monsters aren't in the game when they are. Infact that whole video is disingenuous because it takes a bit from trailer and then shows a random bit with silly stuff in the game to say how something doesn't exist or how things are different. In a sandbox game like this things like that happen, but things like the trailer can also happen. What's important is whether the game has those features in place and so far it does.