Ark: Survival Evolved is a survival game that takes technology (both primitive and modern) and throws you into a monster-filled world. Dinosaurs rule this land, and will gladly make you their next meal. As you advance in levels, more things become available for you to craft: weapons, armor, structures, saddles to ride various dinosaurs, even equipment to allow you to explore the depths of the sea.
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 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 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 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.
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.
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.