If you don't enjoy the gameplay by the first few chapters, you're not going to enjoy the game, simple as that.
The same way you won't come to love a fighting game if you didn't find some entertainment from the first few matches in which you could put up a decent fight, or you won't instantly think a horror game is worth a play if you get more annoyed by the game than creeped out by the atmosphere and design and such.
But don't mistake what you enjoy or don't enjoy with what is good or bad. Games are, ultimately, subjective, and as much as I loathe Call of Duty Modern Warfare 3+/Black Ops I & II and many, many other modern realistic warfare games, to call them bad is simply because I personally don't like them.
Golden guns, Chapt.2 where is handlefor 38 pistol, what checkpoint Chapter 5, clip for 9mmmicro, checkpoint Chapter 14, handle for grenade launcher and stock for Golden RPD, I have all the rest, any help please.