After the hype and excitment this game generated, it is an impressive game, however also has some major draw backs.
The game play itself is what makes or breaks the game. During the game you will take quests from the two factions, weapons store, buddies, underground, telephone posts (assassinations) and you can also get the secret missions from the promotional codes listed on gamespot hints/cheats section.
The fire fights are fun since you have a large selection of weapons from pistols to mortars to flamethrowers, the weapons seem appropriate to the settings and you can do a cool manoeuvre where you slide. Fire fights are not only about the guns about also about the surroundings, for ex if you fire into an ammo pile it will go off sending bullets everywhere or but started a fire you can burn your enemies down (wooden buildings burn as well :P ). This additional element of combat adds to the fire fights to make them more enjoyable and also gives you the opportunity to make what you wish of the situation. When you are on critical health you can heal yourself through a spiffy animation such as you getting out he pliers and retrieving the bullet from you limbs, if you have a broken bone your character will put it back in place or pulling out objects such as sticks and metal shards out of yourself. This again adds to the combat making it feel more authentic in the sense you literally have to mend your wounds instead of taking a "health potion."
However there are a number of negatives to the game, the first being the weak story, or the lack of it. You will be doing a number of quests however why are you doing it? You don't know. Lets just say ive seen porno with better story lines then this.
The second issue is the constant respawn of troops. I am not the only complaining about this cause I have been on forums where many people also complain about this. IN the game you will take out an outpost only to return 2 minutes later and wow its back to new with all the guards back! This becomes frustrating especially combined with the lengthy travel time you experience from going place to place since everytime you get to an outpost you have to kill of the guards or they will come following after you.
The lengthy travel times as mentioned just before are the last issue. There are 5 bus stops on each map (one each corner and one in the centre) which you can quick travel to FROM the other bus stops. The travel time duration only increases as npc's drive on the roads scouting and will shoot and follow you until you kill them off, this means stopping the car killing the dudes, often repairing your car, getting back and in and then continuing with your drive, then do the same at the next outpost and the next set of dudes driving around. This becomes boring and frustrating very quickly.
The missions aren't the best nor the worst. They are very repetitive for example the weapons stores mission you have to travel somewhere and blow a car up every time. However there are a number of different types of missions so there is a variety so you can do one of these and one of those not to get bored of the same thing.
The multiplayer part of this game is imo great. The map editor means anyone can make a map and everyone can play on it, there is a validation tool to see if the map will work or not and the editor is very easy to use. I personally think multiplayer is very fun and well designed, however not yet well balanced since the sniper rifles are far too overpowered.
The bottom line. This game has an awesome game engine which looks great and plays well. The gameplay is excellent both in singleplayer and multiplayer. The positives do outweigh the negatives and this game is definitely worth playing.