First time I ever felt disappointed in a Metal Gear game. Never understood people who said the gameplay was good...it was far worse when it came to how the AI handled being spotted. You couldn't have fun with the AI like you could in previous games either. You get spotted by one dude, even if you kill or tranq him immediately, EVERYONE knows where you are. In previous games, enemies had to have seen you themselves usually, or have been notified by another enemy to know where you are.
Don't even get me started on the story also. Even if you ignore the fact that it wasn't finished, it was still one of the most boring plots ever. I hated the whole vocal parasite plot. It's weird to have such a crazy scenario take place in a prequel and never is addressed or mentioned in games that take place afterward. Also the "twist" people knew as soon as trailers were shown. There was no mystery to this game. Also fuck what they did to Dr Strangelove. One of my favorite characters from Peace Walker.