Two things to note before I get into it:
1. Yes, I beat the game.
2. Yes, I generally hate everything.
Now my quick thought:
An offensively dumb storyline in which you're tasked with saving some of the most contemptible people of this console generation. The gameplay itself is nothing special. Stealth is hiding behind a tiny bush while clueless AI walk 3 feet in front of you, checking out the 34th rock you've thrown from your endless supply. Gun battles involve omniscient enemies soaking up your shots, not unlike the tiger that took an entire clip before it fell. Ubisoft carries over the technique from Assassin's Creed of filling your entire map with icons. Whoa! What's this diamond? Oh, useless bric-a-brac to net you $2. The more outposts you clear, the less emergent gameplay to experience. If you were to clear every outpost, the entire island would be vacant of enemies.
It manages to be a safe game that's technically better than Far Cry 2, but also completely forgettable. Ultimately, I think the best game in this series will be one balanced between Far Cry 2 & 3.