Mercenaries is light on story, has some bugs, a few frustrating design decisions, and is pretty repetitive.
Its also a lot of fun.
The game takes place in North Korea where a war has broken out. The "Allies", identified as the A.N., have placed bounties on several North Korean soldiers, politicians, and businessmen. These targets are ranked as cards in a standard 52 card deck, ala the U.S.'s ranking of Iraqi officials.
You play as a merc that has come to make some money. You can choose between a black American, a white Swede, and a female Asian of English decent. I found these options to be hilariously PC, particularly in a game that relys so heavily on stereotypes.
Which brings me to the factions. There are four factions in the game that you'll accept jobs from to advance the storyline: the A.N., the South Koreans, the Chinese, and the Russian Mafia. Each faction will treat you either as an ally or an enemy depending on what acts they witness you doing and if you do jobs for them. For example, if you kill North Koreans and a A.N. soldier witnessed you doing this, your status with the A.N. will improve. What gets interesting about the faction system is that they will occasionally hire you to perform hostile acts against each other.
The cool thing about the factions is that they'll fight alongside you or attack you on sight depending on your status with them. If they're your friend, expect soldiers to jump onto your vehicle and man its turrets for you. If they are hostile towards you, they will attack you on sight and can become quite a problem, particularly if you have to perform essential missions in their territory.
The faction system is pretty cool, but really isn't as effective as the developers probably wanted it to be. For example, if a faction is totally hostile towards you, you can simply bribe them into becoming neutral towards you again. Its also possible to find a site on the map where a constant battle is ongoing and simply kill enough NK soldiers so the faction that you have a low status with begins to love you.
The gameplay in Mercenaries is the key to this title being so fun. The controls will take a second to learn, specifically the camera controls, because they're a bit different from other console games. Once you get the hang of them though they become second nature.
Your actions in this battlefield do resemble Grand Theft Auto style gameplay. There are things to collect for rewards, missions that can be accepted in any order, a gameworld that is wide open for exploration, and you can jack vehicles.
One cool thing about this game is that its one of the VERY few that actually lives up to the hype behind the statement: "You can complete missions any way you want." You can. You can go into a place and blow the shit out of anything, or sneak in. You could snipe people from a distance or fly in with a gunship. You could infiltrate a base in a civilian car or carpet bomb the shit out of it. Its your choice.
That leads me to the Merchant. The more stuff you collect and the more missions you do for the Russians equal more supplies, vehicles, and air strikes you can call in whenever and where you want. The merchant will swing the tide for you more than once.
And I can't say enough about the carpet bomb. That special attack alone is worth the price of admission.
There are hoardes of different vehicles to drive and weapons to use. From cargo carts to M1 tanks to Apaches to your feet, you'll be doing a lot of traveling. And from the end of you gun to C4 to carbines to rocket launchers, you'll be doing a lot of killing. (I killed over 4400 people on my way to victory.)
There's a ton more, but I don't want to be typing all year, so let me get to the bad stuff.
The physics engine has a few glitches, particularly in vehicles. Tanks seem to have a problem with items on the road and will bounce like they hit a trampoline. Its rare that that occurs, but it can be annoying. Its not like the tank flies through the air, but its enough to alter your course.
The game is a bit repetitive, but what game isn't. Its a war game so its all guns and action. Don't expect an engrossing storyline. The fun factor will keep you into it.
You can't save during missions, and that generally isn't a problem since missions don't take very long and you can save at any other point. However, the "Ace missions" can take a LOT longer and are MUCH, MUCH harder than anything else in the game. A save feature doing these missions should have been incorporated. I wouldn't have even brough this issue up if it weren't for the last level. If you play the last level "by the book" then it can take you an hour and its LOADED with respawning helicopters, tanks, and NK soldiers. Not to mention all the "traps" on that level. I'd go into detail, but it'd involve spoilers. Ask and I'll dish the dirt. Needless to say, I was NOT a happy camper for the last few days as I struggled to beat the last level. This is after not really having any problems with the other 51 cards and various other missions. Had I been able to save, I would have finished the game days ago. Some designers would say the lack of a save increased my gameplay time, I'd say its MY time, not theirs to decide how I should spend it. Making someone play a level over and over isn't good design, its a lazy way of trying to make the finale seem tough. They should have allowed for a save spot halfway through the mission.
Let me also mention the AI. Its stupid, yet smart. They'll seek cover, flank you, man turrets instead of using their rifle, throw grenades, etc. However, they'll also stand around while their friends die, leave your vehicle for no reason, drive their tank up a wall until its verticle, etc. The AI does enough to support you, but more in the "bullet stopping" way rather than an "enemy killing" way.
Still, I have to give this game a big thumbs up overall. Its a ton of fun and at times completely chaotic. Good controls and wild battles are exactly what one should expect from a game set in North Korea where you play as a merc.
8 out of 10.