Far Cry 2 really only had a few simple problems, but unfortunately they were all fundamental to solid gameplay mechanics:
1) So I'm solo in the jungle playing Rambo in a proper day/night cycle, where the **** are my nightvision goggles?
2) WTF is wrong with the mortars? They're almost impossible to use, you can only carry three rounds, and your guy fires them off at a rate that might impress continental drift.
3) Who came up with the mega asshatery of the money system? I got to the end of the game, having completed every single mission, side quest, treasure hunt, and I still couldn't buy every freaking weapon/upgrade/vehicle. Any game that doesn't give me every weapon by the end of it is a game not worth owning.
4) The ending of this game made me suicidal; it's about as brilliant as self-immolation. I hope everyone involved is strangled to death by their children.
Sorry, been wanting to get that off my chest ever since I played it.