I don't know why people choose to play 1-6 of a franchise and get upset every time the game isn't completely "different".
If you've played a couple farcry games and you decided to play this one.. You're playing because you like the style of game farcry brings aren't you?
I enjoy farcry because to me it's one of the best coop games out there. Yes, it's a similar play style to the last one, but that's why I bought it. That said, to me it's definitely best played with a friend. The animal companions are kind of cool, but there wasn't much thought put into them. I really like the game, but having no companions with a back story means I pretty much turn the game off until a buddy is on. Which again, I'm fine with because that's my reason for playing farcry.