Frankly, my dear, this is a disappointment
FCIP is not worth the extra expense if you've already whetted your appetite for destruction with last fall's truly excellent XBox game. The visuals aren't spruced up enough (save for the water, which does look really nice) and even the minor bugs from the original, such as the muted dialogue mixing, haven't been corrected. There was plenty of time to remake the original game, add in the new content, and produce a real winner. Ubisoft elected to push this out into the marketplace quickly, and it's just not as satisfying as it could be.
The core gameplay is still very good, but what the hell is up with the nuttiness? You can be locked on to a target's head, but one shot doesn't kill. Or you can have an enemy near, but not in, your sights and still clip him. Also, at times you can be shot while hunkering down inside one of the makeshift island bunkers, but you can't return fire through the same walls? Weirdness abounds.
The achievements require a lot of time and effort, too. 100 headshots is worth only 30 points? They don't even throw you a bone for little level clearances along the way? Damn.
All that said, FCI:P is still a pretty darn enjoyable game if you avoid giving it the discerning next-gen eye. There's a terrific multiplayer with good variety to the maps and the games themselves, and the single-player episode, flawed as it may be, has plenty going for it if you haven't ventured into the Far Cry series yet. The game is undoubtedly a victim of its own hype and expectations, because its wondrous debut on the PC and the exceptional XBox game had us all anticipating greatness from this one.