This game was OVERLY hyped up. Don't believe what they say the game is very tedious.
This game SHOULD ONLY BE BOUGHT FOR THE SINGLE PLAYER. The game is fun many times but becomes repetitive. The boss fights are very easy and all you do is shoot them. They rarely will be able to hit you. I personally liked the missions with people. The has way too many machines in it. It makes the game feel VERY fake. It's always the same sneak by someone. I have sneaked whole levels without being seen. The octocam (camouflages with anything) makes it too easy. A couple of missions were good including ones where you follow someone. That was very fun. There are way too many cutscenses and gets annoying after a while.
Multiplayer
MULTIPLAYER IS HORRIBLE. One of the worst I have ever played. The only way to kill someone is by shooting in the head. If you don't the other people will kill you easy. The reason is the health bar is HUGE. Learning curve for multiplayer is big. Many will kill you easy. Also everyone uses only two types of guns. Snipers and assualts. It's boring because everyone is using the same gun.
Overall
Single player was fun but it is boring at the end. Multiplayer is not worth buying the game.