It had potential, and there was some fun to it, and if you forced yourself into a bit of variety by changing weapons, that definitely extended the lifespan somewhat, but yeah, a whole loads of flaws that stopped it being a top game. Group AI that completely rendered any attempt at stealth often pointless (take down a single guy, out of sight from everyone else, with a silenced gun, and yet they all still get alerted? Psh), an utterly irrelevant and terribly implemented faction system (EVERYBODY shoots at you in the wild, NOBODY shoots at you in safe zones), and a plot so tiresome you can't begin to care about it (the Jackal BOOO, except wait no, maybe YAY, I think. Haven't you lost interest yet? Go away).
I'd have loved them to have taken a leaf out of GTAs book and actually tried to make it more like a living, breathing, African state in turmoil. Proper towns, villages, people that aren't army dudes going about their daily routines. Baddies that try to stop you rather than shoot on sight. That kind of thing.