This game is wildly underrated, especially after the last patch which lets you adjust the camera FOV to RE 4 levels and wider. The raw mechanics of the game are top notch for any TPS, considering the amount of tools at your disposal and the variety of enemies that you encounter. Scenario design is definitely more uneven (sometimes comically ridiculous) than would be expected, but one campaign has more going on than most games as a whole. Reminds me of DMC 1 in that they let you perform everything your character is doing, not just watching a token cinema, even if it is jarring.
The Dark/Demon's Souls style agent hunt mode adds a lot to the game which rarely gets mentioned. Finally activated it today and the two guys that "invaded" made the game more challenging and fun on normal than professional. Coop mercenaries is definitely best part of the game though since there is no garbage scenario BS to deal with and can just focus on the core gameplay.
While I could see how people disliked it if they used 1/10 of the options available and played it like some generic cover shooter with the formerly claustrophobic camera, there's a lot of fun in the game if you experiment to play efficiently at all, especially in coop (naturally).