Red Faction Guerrilla is all about destroying things. You play as Alec Mason who has come to Mars at the urging of his brother to work as a miner. It's not much of a spoiler to tell you that in the beginning his brother is killed as this forms the basis of the story and the motive for Mason to join the organized rebellion that's currently under way. Although Mason is a pretty cool dude who sounds and acts mature, you won't be getting any in-depth characterization and the story is by no means complex.
Mars is controlled by the Earth Defence Force, and unhappy with their oppressive regime, the workers formed the Red Faction resistance to fight back. The premise is to cause as much chaos and destruction as possible so that the EDF will pull out of specified areas. Once you have achieved this, another area opens up and you rinse and repeat until all areas of colonized Mars are free.
There are several types of missions to accomplish your goal. Destroying EDF properties and bases, rescuing hostages, stealing special vehicles, attacking convoys, and generally creating as much pandemonium as possible. At any time, you can use vehicles parked at the Red Faction bases, steal them, or co-opt them from civilians. There are also timed runs for getting stolen vehicles back to the RF bases. Some of these require travelling through several large areas and are quite challenging. Much of Mars geography is very mountainous with serpentine roads winding through them. You also have to contend with other vehicles using the roads.
Vehicles are a big deal in this game and there are lots of them. It's a vast open world and you absolutely need to drive. The good news is that mechanical controls are done right, although each vehicle type handles differently. They can also be used as weapons of destruction creating interesting results. Vehicles you use in an area will show up in base camps, so grab as many different kinds as can. Once you get the ability, you can also fast travel to the bases.
There is a morale meter for each area, which measures the support of civilians. The higher the morale, the more help you will receive from them during confrontations with the EDF. Morale needs to be high to get faction support on missions, determining the number of supporters who will jump in to help and the amount of ammo in crates. This level will go down if you get killed and you will respawn at the nearest base camp, even if you have a save at the mission site. This can be a real pain in the butt if you were a considerable distance away from the base when you died and want to go back to where you were. The only exception is on main mission retries where you will respawn at the location you picked up the mission. However, side missions will remain available if you want to try again later.
Red Faction Guerrilla is very good at what it does, which is physics. Destroying things is a shit-load of fun and to that end you have a large variety of vehicles and weapons with a few mechs thrown in and the all important sledge hammer. The way the buildings come down is very impressive, but the mechanic allows for all sorts of fun and games. However, I found that some of the missions can get very wearing because there is a lot of repetition to a certain extent. Especially since all load saves and respawns put you at the safe house and it's often not an easy drive back to where you want to be. So, try not to get killed or you can end up driving the same route over and over again.
The house arrest missions gave me all kinds of trouble as hostages once freed will wander into the middle of a fire fight and won't follow you if you get ahead of them. You need to stick around and kill most of the EDF first and protect them. They also can't jump over things, through windows, or from second stories.
The side character, Sam, works on making new types of weapons from any salvage you can find. Weapons are fairly traditional, but bullets are not very effective and I ended up sticking with the same 4 weapons for most of game. Melee is better if you are close. However, you can destroy things with vehicles, bombs, a rocket launcher, or a rare mech if find one. There are several different types of sledges as well. The sledge is also used to mine outcrops of ore which produce crystals to purchase upgrades. There are 300 of these and you have to explore off the beaten path to locate them all. Salvage from downed buildings can often be pretty scarce and upgrades get more expensive as you progress. There are also 36 well-hidden radio tags to find, which will give you some back-story. Each one you find will add a MOAB location to the game, which you can drive over to collect.
Once the game is completed, and after the credits, you can go back in to mop up anything left unfinished. The enemies have become harder though. It also unlocks insanity mode.
Putting all seriousness aside, the game can be a whack of fun just doing silly things to see the physics in action. All DLC is included in the Steam version, however, I did not find the single-player bonus up-to-par with the main game and got bored with it pretty fast.UPDATE Oct 2015: In Dec 2014, Nordic Games released Red Faction Guerrilla Steam Edition, the only edition available now. The game is automatically updated through Steam and information around the internet dated before this may be outdated concerning patches and mods. If you have an older non-Steam version with proof of purchase and/or a CD key, Nordic Games may give you a Steam key if you contact them and select Support Department. If you owned the game on Steam previously, GFWL has been removed and the first launch will attempt to migrate your saves and achievements. New content and DLC, other than the soundtrack, are also included in the Steam Edition.