This game is great, until you really get into it...
But the ai is something special. You just dont see many games where usually about 1 out of 4 enemies blatantly shoot through walls. They will even move themselves to be out of line of sight on purpose frequently making it an annoying hide and go seek game chasing down a guy that can connect with his shots with unerring accuracy no matter the range or if your bobbing and weaving.
This is not so bad until you get to about the 50% mark in the game where they start giving the enemies mortars, sniper rifles and rpg's. At this point the game just almost completely falls apart, and unless you enjoy using only stealth constantly the games other mechanics just take a dive.
Vehicles become instant deathtraps meaning travel through the open world (that has maps that funnel you through constantly respawning enemies) becomes very painful, and virtually everybody on the island you encounter is hostile the whole game. At least the game Mercenaries had factions you could be friendly with so this feels like a step back.
Another minor problem but an annoying one is that enemy npcs can move REALLY fast sometimes. Ive seen npcs running around that can move as fast as cars. Combine this with a flanking ai mechanic, and you'll swear they just appear behind you at times and i think they may spawn around you as well. Toward the end of the game they'll just start sending 2-3 vehicles with mounted grenade launchers or heavy machine guns on your backside as soon as you encounter something to the front which just gets annoying.
Overall this game was destined for an 8.0 or even an 8.5, but due to these problems i cant give it more then a 6.5. There arent even any mods out there that i can find or the score might have gone back up, but i cant imagine how anyone could enjoy the gameplay after a certain point in the games current state. This would have been a very easy fix. I just dont understand fps companies today....