A man and his rag-tag squad are secret agents for the British. In the 70's they in the American southwest in the middle of nowhere on top of a large rock pillar overlooking a drug smuggling...camp...thing. Anyway the protagonist is wielding a lever action and in his bored (he and 4 others are guarding the rear while 3 more sit atop the pillar (which as a not so steep slope in the back which can be used as a road) sniping people in the camp. The protagonist sees a statue in the cave holding a staff; out of curiosity he grabs the staff. Farther back in the cave he hears a noise and slowly backs out with the staff. As he exits the cave 9 giant swordsman statues come out after him (they're alive now) he and his companions narrowly escape in their jeeps. The swordsmen are out to get you and you must hunt them down and kill them, the best way is to use the staff. The AI is really good and actually useful (that's about the craziest part of the game har-har) and when you drop the lever action or staff to pick up another weapon, one of your teammates will scurry over to you and pick up the weapons you dropped. Halfway through the game (in 2011, yea it's a long game) you "die" only to wake up again in a chryo-tube (see futurama) sort of thing in an abandoned ghost town that was formerly a large city. There are no enemies to fight, you just have to fin your way out. It turns out there were more then the 9 swordsman, there were 9 more and an army of smaller ones. Before you "died" you hid the staff and you must now find it. The swordsman have been waging a war on humanity since you "died" and only one of your former squad mates is still alive. He now leads a small army and when you reunite with him, he is cornered by one of the swordsman. You don't have the staff yet and you have to fight said swordsman without it making it especially difficult. There is no final boss, just a huge, and I mean huge battle with the smaller swordsman army at the end.
Or you are in a sort of gladiator arena...thing with different types of matches. You don't know who is running the arena. You and your team must eliminate the other team in order to win a match. The catch is, each match is weapon type specific, like heavy weapons, pistols, shotguns, assault rifles, sniper rifles, and gauntlet (online only) where you and your team fight increasingly harder waves of bad guys with whatever weapons you choose, unlimited ammo, but scarce health packs (that's right, health packs). You where a special collar that prevents you and everyone else in the arena from dying, and allows you to respawn. It's kind of like Battlefield in the sense that you have to kill x number of bad guys to win. As you proceed the battle become increasingly harder and eventually mechs and choppers and tanks are introduced into the heavy weapons matches. You get more points for melee kills and headshots etc. When you begin a match you can shoose what type of gun (that is allowed in the match) to use, as well as a sidearm (for heavy weapons matches, the sidearms are SMGs) and melee weapon and the more points you get in a match, the more weapons you can unlock/buy.
