Recs.
Updated
SpecsUpdate
Pros
Pro You can tame and mount nearly every creature in the game
From the small, quick raptor to the massive, vicious giganotosaurus, you can mount nearly any dinosaur in the game. There's huge, flying dinosaurs, aquatic dinosaurs, some that are like walking fortresses, and others that can take those down.
Pro The game makes you want to explore, craft, and fight to make the most of its progressive crafting system
Ark is unlike many survival games in that you attain levels as you progress. As you level higher and higher, you gain access to more craftable items. Some are just more powerful versions of lower-tier items (such as leather armor vs. cloth armor), but most are brand new (such as firearms, scuba gear, and saddles for more powerful dinosaurs). This really drives you to explore more areas to find rarer resources and fight stronger dinosaurs.
Pro You can share materials, dinosaurs, and structures by forming a tribe with your friends
Users can form a tribe with other online users to for a community. This community can now band together in order to build and grow as well as team up against other tribes. This makes for a fun experience with friends and other players as it requires teamwork in order to be successful.
Pro Stunningly beautiful
The landscape, creatures, structures, even other players are all gorgeous. The textures are seamless, and the character/dinosaur models are just great. The environment ranges from lush green forests, to snowcapped mountains, to incredible coastal views. When you combine all of these things, it adds up to being simply breathtaking.
Pro Increased customization thanks to player-created servers
Ark has hundreds, if not thousands, of great custom servers. You can control things such as PvP, experience, gathering, and taming rates, set things up so there's no griefing (constantly bullying a player or group of players), and the difficulty of the creatures.
Pro No longer Early Access
As of the 29th of August, 2017 the game is no longer in Early Access.
Cons
Con New player starts can be ridiculously hard
The new player experience is crude and made randomly dangerous by the developers. You start on a beach, but that's not safe, you can spawn right on top of a deadly dino and get rekt before the spawning animation will let you react. There are raptors set to roam the beaches too, and those are death to any player which hasn't leveled up and knows how to kill a killing machine with a breakable spear. When you die you respawn in a random location, even when choosing the same spawn spot. Know that stuff you collected on your last life? Good luck getting to it unless you got a lucky roll and spawned in the same spot. Otherwise, just forget about it and start all over, the decay timer is set very low and you'll never make it back. So yeah, the new player experience is rough and unnecessarily so. Again, a good private unofficial server with people who will come over and help you survive to level 5 is your best bet for enjoying your first several hours of the game. Otherwise, you will not enjoy them and likely quit, and all of the fun is on the other side of those hours.
Con Official PvP servers despoiled by alpha tribes
Ark has the "alpha" tribe meta going on, where a tribe will rule a server. They routinely wipe all other players' habitats and dinosaurs off of the server for fun, and they also roam to other servers (which Ark supports) and do the same there. They also use every exploit available in this Early Access, very unfinished game to ruin access to the game for anyone on the servers, such as pillaring / turreting critical resource-gathering spots, releasing extremely high-level tames onto the beaches to kill all new players, etc. Your best bet is a good, private unofficial server, but you'll have to do your own research to find one. Good luck!
Con Taming / raising dinos takes hours to a day of real time
Taming a low-level dinosaur will take nearly a solid hour of real time, during which you must protect the dino as any predator dino will go right for it. Raising a dino from an egg can take a solid day - as an example, raising an Argentavis with friends will need a special raising process which can take over 12 hours to complete. That's not a hard dino to raise either Look to the Ark wiki or the Dododex site and you'll see some insane numbers there for top-level dinos. So be very aware there's both a personal level grind (many people spend many hours crafting things far past useful quantities just to get levels) and a dino tame grind which can be just unsupportable for anyone with an actual life. Good luck!
Con Anti-cheat issues
ARk has started using an anti-cheat tool called Battleye, this has so far broken Linux and Mac support for using official servers. Battleye has also had some issues with banning legit users and does not have a very good reputation. These issues add up to many angry players who paid for the game but now can not play it.
Recommendations
Comments
Flagged Pros + Cons
Pro You can share materials, dinosaurs, and structures by forming (or joining!) a tribe with your friends
Users can form a tribe with other online users to for a community. This community can now band together in order to build and grow as well as team up against other tribes. This makes for a fun experience with friends and other players as it requires teamwork in order to be successful.
Out of Date Pros + Cons
Con Early access
Ark is an early access game meaning it is basically in an Alpha or Beta state. Bugs are easily found and many areas of the game lack polish. While it may not cripple the gameplay this is something to consider when purchasing as there is no guarantee the game will ever be finished.