I think it's kind of dumb that they have special ops guys using crossbows...
And the game isn't very historically accurate..
In the mission where you are in Hue, during the Tet Offensive. He throws you a shotgun and says, "Heres a SPAS-12." But it will be more than 10 years later that the SPAS-12 would be manufactured. As well as the FAMAS(still being designed at the time, wasn't produced untill '78, like the SPAS, and the AUG wasn't produced then either.)
Plus I found in single player that the enemies tend to ignore the hell out of your teammates, and melee rush you like there's nobody else, annoying as hell. Not to mention the guy you have to "follow and protect" getting stuck in walls and having to restart the damn mission.
Just my two cents.