Started playing the campaign today and I have to say it's absolutely horrible. I made it to the second mission before the game became absolutely impossible to play.
The first mission was nice and worked well. Quite railroaded but considering that it's was a short introduction mission it's understandable.
Now, the second mission. I died for the first time in the first breaching part (which has a very neat mechanic where you can decide how to breach btw) because I didn't notice a guy crouching behind a box. Also, for some reason the damage you take is very inconsistent: during normal combat you can take a lot of hits, but in that breaching section one burst was enough to finish me off.
The main problem was with the checkpoint. I reloaded from checkpoint and started in a situation where I had already breached the door, there were no enemies in the room in front of me and someone started immediately shooting me. The worst part was that I couldn't move at all. I couldn't shoot, I couldn't turn and I died. This happened every time I loaded the checkpoint so I had to start the mission all over again.
So I began the mission again and advanced and all of a sudden during combat I started taking hits even though I was completely behind cover. Just before I died I saw a friendly guy shooting at me and he was the one who killed me. I hadn't left the combat zone, I hadn't shot at him and he still killed me. I had to restart the mission again. However, now that I had started the mission again, all of the friendlies started shooting at me right at the beginning. I walked 2 meters and was instantly shot at and killed by my own guys for no reason.
Seriously, don't buy this game. It is a total waste of money. Give your money to someone who will cut your dick off rather than soending it on this game. I promise you that losing your manmuscle is much more preferable than playing this shit.