America's Army America's army is a multiplayer combat simulation released by the US Army. You take on the role of a soldier in the army as a member of one of three fireteams. 

ARMA II ARMA 2 Free is a free version of one of the most realistic battle simulation games on the market. The game focuses heavily on team cooperation and squad tactics. Many different vehicles and aircraft are featured in the game including tanks, jets and helicopters.

The major drawback to this version of ARMA 2 is the lack of support for HD graphics and user created mods. Another downside is that the single player campaign is absent in this free version. Despite the drawbacks, the game is definitely worth trying if you don't want to shell out for the standard edition. 

War Inc. Battlezone (3rd Person) A new addition to the steam free to play list of games, War Inc. Battlezone is an shooter along the same lines as Call of Duty except in third person. The overall quality and production values of the game seem pretty good overall, however you may encounter occasional artifacts and frame rate issues. There is a decent variety of game modes to choose from ranging from capture the flag to securing locations, much like similar games of this genre.You play the game from a third person point of view, which is different from most games of this type, giving you a wide view of the battlefield.
Note: This is a 3rd person game but I felt like its worth mentioning. 

MicroVolts MicroVolts is a third person action game with four characters to choose from and a variety of weapons to use during battle. You can customize your character cosmetically to suit your tastes. One of the neat features is the ability to switch between weapons during battle which adds an interesting strategic element. There are a few different game modes including capture the flag, deathmatch, and free for all. Once you reach higher levels in the game you can unlock better weapons. The game is fun in short bursts, but it may not keep your interest for months on end when compared to a game like Team Fortress. 

Tremulous Tremulous is an FPS game with strategic elements where its humans versus aliens. Having two distinct factions with different ways of playing, much like Left 4 Dead, makes the game unique to most FPS games. The graphics and sound in the game are slightly dated, but the extremely fun gameplay makes up for it. There are classes focused on building as well as pure fighting classes. Humans can upgrade their armor while aliens can upgrade their body. 

Lost Saga Lost Saga is an online action fighting RPG featuring a wide variety of characters to choose from. You can equip characters to keys so you can switch between them during battle. The graphics are pretty good for a free game and have an anime style. There many different maps to try out. The game includes a good variety of game modes to keep you entertained including PowerStone, Prisoner, and standard Deathmatch. 

Air Rivals Air Rivals is a flying MMO where you are a pilot taking on missions and fighting in a war between rival factions. Depending on which zone you are in, you will encounter player controlled enemy ships ready to blow you out of the sky. You can level up like most other MMOs but there is also a skill factor since you can outmaneuver your opponent if you have superior dogfighting abilities. At the end of the day there is a still decent amount of grinding involved, but its worth a try if you like the idea of flying around and blowing people up. 

C&C Red Alert This is an older RTS game that has been released for free by the studio. In its time, it was one of the most amazing RTS games ever created. You fight on the side of the Allied or Soviets through a wide variety of missions ranging from standard destroy the enemy base to commando missions. The balance and different types of units you find on the two different sides is pretty solid. One of the unique things about the C&C franchise is the live cutscenes, and this game is no different. A fun game to pickup if you want to relive the glory days of the C&C franchise. 

The Last Dance The last dance is an indie game that takes place in the mafia times of Chicago in the 1930s. You play the role of John McClain, a former police officer who is investigating the murder of his wife. The game has a unique art style, probably worth a try. 

Dead Frontier (Browser Game) Dead Frontier is the ultimate survival horror MMORPG. Log in and play with thousands of real players from around the globe as you struggle for survival in a zombie infested city.  

Avalanche Avalanche is an action game set in the Final Fantasy VII universe. The game features fast paced hack and slash gameplay played from a third person perspective. Most of the time you will be surrounded by enemies which you will defeat using your weapons and abilities. 

Alliance of Valiant Arms Alliance of Valiant arms is an MMO FPS with high production values and fun gameplay. The game features a wide variety of game modes including escort missions and demolition. The game features commercial quality graphics due to running on the Unreal 3 engine. The three classes available are the pointman, the rifleman and the sniper. 

Phobia Phobia is a neat student game I found on DigiPen. You play the role of Max, a monster trying to scare people in the town. The more people you scare the stronger you will become. Your enemy in the game is light, you must avoid it at all costs. 

The Blob The Blob is a 3d game where you are a ball of paint rolling around a city. You can paint just about anything in the city. Your primary objective is to paint all the landmark buildings in the ciry. A nice little game that should keep you entertained for a short while. 

Attack of the 50ft Robot Attack of the 50ft Robot is a student game from DigiPen where you control a robot trying to destroy everything in your path. The graphics style is that of an old 1950s movie. 

Bear Go Home Bear Go Home is a platform game with a cool unique art style. You never get to directly control the bear, you can only do things like stretch and squish the bear to help him overcome obstacles. The unique game mechanics make this a great one of a kind find, give it a go. 

Empyreal Nocturne You play the role of head bird, use your skill and the birds in your flock to defeat your enemies. You can sacrifice one of your birds to give yourself a small boost. Manage your flock wisely, although they replenish, you don't want to be caught without a decent defense against enemy attacks. A fun and unique game that should keep you entertained for a short while. 

Ballman Place Ballman Planets is an addictive and extremely fun tribute to the classic Pacman game! Of course, there are balls, power ups and ghosts... each of them with different characteristics and behaviour (check out the lovely blind green-ghost!), but also there are many different planets and cool springs that allow you to jump from one planet to another! With its innovative fully mouse-controlled action and stunning 3D maps 

Face of Mankind Face of Mankind is a first person Science Fiction MMORPG with heavy emphasis on PvP and crafting. The graphics in the game are a bit dated compared to modern MMORPGs or FPS games.  

Genesis AD Genesis A.D. is a first person shooter featuring three classes: support, sniper, and assault. The game features a nice variety of well designed maps and weapons. The graphics quality in the game is very solid. 

Knytt & Knytt Stories The Knytt was abducted by an alien! Traveling through space, the UFO flies into a meteor and crashes on a nearby planet. Luckily, the Knytt and the alien survive, but the UFO is a wreck. How can the Knytt possibly find its way back home again? Knytt is a free platform game for Windows featuring exploration, atmosphere, and infinite cuteness. 

Project Blackout Project Blackout will test your skills as gamer with fast paced action, precision shooting, and twitch response times. Project Blackout's graphics, surround sound, and camera effects will put you in the middle of the action and test your skills at a whole new level. Lock and load! 

Iji Iji is an action-packed strategic platform shooter with a detailed story, large levels with multiple paths, powerful bosses and lots of secrets. There are alternate gameplay events, dialogues and scenes depending on what you do, a wealth of extras and bonus features, and seven stats to upgrade through a leveling system. Iji herself has superhuman strength and abilities, and can crack Nanotechnology, use her enemies' most devastating weapons against them, and be a pacifist or a killer - the story adapts to how you play.  

Warsow Warsow is a multiplatform first person shooter with cartoon style graphics. The gameplay is extremely fast paced and features a large variety of game modes including: Capture the Flag, Free for All, Team Deathmatch, Clan Arena, Instagib, Race, Duel, Team Domination, Bomb & Defuse, and Headhunt. You can also get the game on Mac and Linux in addition to Windows. 

Cave Story Cave Story is really one of those games that can be considered a masterpiece of game design. There are so many wonderful and classic gaming elements, that I cannot even begin to describe just one quality well enough to say "It is for this one reason alone that Cave Story is a great game." There is just so much effort, originality and ingenuity behind this game and it really shows more and more as you play through it. 

Quake Live (Browser Game) QUAKE LIVE is a new and innovative multiplayer game experience from id Software - the creators of DOOM, WOLFENSTEIN and QUAKE - that offers players of all skill levels an easily accessible multiplayer game and community through a single website. The game can be played totally free, though there are paid subscriptions with even more features and play modes available. For more details on the great additional features of a paid subscription, please follow this link. Every element of the QUAKE LIVE experience, from finding and playing games to post match stats review and social networking are delivered through a single state-of-the-art website. 

Super Mario Bros. X Super Mario Bros. X is a massive project that blends elements from Super Mario 1, 2, 3, and World. It has many power ups, such as the Hammer Suit, Tanooki Suit, Kuribo's shoe, The Billy Gun, and many old and new Yoshis. Super Mario Bros. X is a massive project that blends elements from Super Mario 1, 2, 3, and World. It has many power ups, such as the Hammer Suit, Tanooki Suit, Kuribo's shoe, The Billy Gun, and many old and new Yoshis. 

Urban Terror Urban Terror™ is a free multiplayer first person shooter developed by FrozenSand, that (thanks to the ioquake3-code) does not require Quake III Arena anymore. It is available for Windows, Linux and Macintosh.

Urban Terror can be described as a Hollywood tactical shooter; somewhat realism based, but the motto is "fun over realism". This results in a very unique, enjoyable and addictive game.  

Tribes A little over a year ago, Vivendi shut down the Tribes 2 master servers. Many saw it as the end of an era, but a group of dedicated gamers created their own multiplayer patch to replace it, called Tribes Next. Tribes 2 then became free for anyone to download and create an account for. This ushered in a revival as thousands of players came back or even began playing for the first time. 

Alien Swarm Alien Swarm is a game and Source SDK release from a group of talented designers at Valve who were hired from the Mod community. Available free of charge, the game thrusts players into an epic bug hunt featuring a unique blend of co-op play and squad-level tactics. With your friends, form a squad of four distinct IAF Marine classes. 

Team Fortress 2 Team Fortress 2 is a class based action First Person Shooter. It was originally a commercial game but has been released as free to play. The classes in TF2 are as follows: Scout, Soldier, Pyro, Demoman, Heavy, Engineer, Medic, Sniper, Spy. Each class has a very distinct way of playing, for example as the engineer you can build turrets or as the spy you can disguise yourself as the opponent team.

TF2 features extremely high end graphics and production values not found in most free to play games. There is a large player base very dedicated to this game. A must have game if you did not purchase it when it was commercial. 

Battlefield Heroes Battlefield Heroes is the first Play 4 Free game from EA. Create, customize and level up your own unique war hero, then take them into battle against other players of your skill level. Use your special abilities to destroy the enemy, or support your friends.  

Wolf Team Wolf Team is a fast paced 3D MMOFPS that features the ability for players to transform between playing as a Human or as a Werewolf. Humans have an assortment of weapons available at their disposal giving them an advantage at a distance. Wolves on the other hand have no ranged attack but are faster and stronger than their human counter parts.  

The Hunter The Hunter is the most realistic hunting game in the world and the extraordinary realism and compelling gameplay are not the only things that set it apart from the pack. It is a global social experience, with hunters immersing themselves in the thrill of the chase and so much more. The hunt is on!  

Cross Fire Cross Fire is a free online first-person shooter featuring persistent military rankings, an integrated clan system, and five exciting game modes, including the exclusive stealth-action Ghost Mode.  

S4 League S4 League is a 3d sci-fi shooter with a third-person view and a techno beat. Play Death Match or Touch Down (capture the flag) modes and earn money to purchase new weapons, skills, clothes, and hair and face styles. S4 is a fast-paced, skill-driven game where even beginners can defeat high-level players.  

Subspace Continuum Ever imagine what it'd be like to play Asteroids against your friends? Want to savor the satisfaction of blasting people out of space in some addictive side-scrolling 2D spaceship shooter action?

Slap on some snazzy graphics, guns, bombs & big explosions and the beautiful revelry of flying past your enemy's debris as they cuss at you, and you have Continuum, the longest running massively multiplayer spaceship shooter game running today. 

Combat Arms I have been playing Combat Arms for about a week now. In my opinion it is one of the best free first person shooters you can find. I have played a lot of fps games, commercial and free and this one is right up there with the best. Once you register and setup a username, you get to choose your players basic identity. You have the option to purchase various weapons, modifications, armor, and other gadgets to help you win. If you have ever played CounterStrike then you will be right at home in this game. The game feels and plays a lot like CS.

There are different game modes but personally I only play elimination, which consists of two teams trying to reach a set amount of kills, usually 140. I also like the one man army game mode which is basically a free for all. There is a variety of maps in the game, from large sniper friendly maps to small sub machine gun friendly maps. My personal favorite map is Junk Flea. The competition in this game is pretty varied, but for the most part, your opponents are pretty average compared to a game like Counter Strike. This is mainly due to how new this game is. I find this to be great, since I love to beat up on noobs, as I am sure you will as well.

As a new player starting out I will give you some basic tips to help you survive. First of all, buy heavy armor and a helmet to help you survive longer. As for weapons, I personally like the SCAR, AK-47 and UMP. All the guns in the game are pretty good if you get in a bit of practice. If you are using a sub machine gun on a small map like Junk Flea, avoid places where you have to shoot long distances and strafing works wonders, especially against average people with rifles. The sub machine guns are great for new players because of the low recoil and mobility.

When you get kills, at the end of each game you earn experience and cash which you can use to unlock and buy more stuff for your character. Overall this is a great game you should definitely give it a try.  

Drift City Drift City is unlike any driving game you'll ever play. Part role-playing game, and part racing game,Drift City will keep your pedal to the metal in your quest to become the ultimate driver!  

Dogfights Download the free episodic game and participate in amazing 3-D recreations of the air battles that shaped history. Play DOGFIGHTS: THE GAME and participate in amazing 3-D recreations of the battles that shaped history. DOGFIGHTS: THE GAME re-creates the battles seen on Dogfights the series with amazing realism. It is an incredible, immersive experience that requires a PC with a video card capable of displaying high-end 3-D graphics.  

DBZ Mugen 2 This is a freeware combat game whose main attraction is that you can play as the characters from the animation Dragon Ball. Apart from that, it is a very complete arcade fighter, with four modes of play; arcade, versus, team battles and training. An enjoyable freeware title, especially if you are a fan of Dragon Ball.  

Assault Cube AssaultCube, formerly ActionCube, is a free first-person-shooter based on the game Cube. Set in a realistic looking environment, as far as that?s possible with this engine, while gameplay stays fast and arcade. This game is all about team oriented multiplayer fun. Also make sure you check out Cube 2 if you like this game. 

Dino Hunters Prepare for a never-ending trip over land and sea; a bloody battle against prehistoric beasts, modern-day spies, and futuristic mercenaries. This non-stop war through space and time is waged against an ever-changing enemy and arsenals of ever-evolving super-weapons! Whatever your specialty: urban combat, jungle warfare or the ultimate space odyssey, DinoHunters has it all wrapped up in this one-of-a-kind, massive multiplayer game!  

Fighter Ace Welcome to the world of Fighter Ace, a 3D massively multiplayer aerial combat game with a community of thousands. Strap yourself into the cockpit of any one of 107 World War II vintage fighters and bombers before taking to the skies against hundreds of other virtual pilots. Watch your six as you join in the most notorious battles in history as an Ally or an Axis Power. Fly for Germany, Japan, Great Britain, Russia or the United States in detailed and accurate terrains including Guadalcanal, Midway, The Battle of Britain, and Kursk. Any way you fly it, Fighter Ace is an exhilarating, real-time experience every time you play. Offline play offers eleven training missions, five practice arenas, and three arenas with different flight physics levels. NOTE: THIS GAME IS NO LONGER SUPPORTED FOR MULTIPLAYER HOWEVER YOU CAN DOWNLOAD THE OFFLINE VERSION 

Soldier Front Soldier Front is a 3D FPS, focused on the hardcore gamers. Soldier Front offers a totally new type of FPS. Soldier Front offers realistic game play and graphics, but also offer a character growth system allowing gamers to retain their stats and rise through the ranks like a real soldier. Soldier Front is the next step in FPS gaming.  

Dispatch of Army Dispatch of Army is a Massively Multiplayer Online First Person Shooter that delivers the kill-or-be-killed experience in the combat environment of the 60s. The game features 3 game modes which provide even the most hardcore gamer with palm sweating challenges through detailed jungle and urban warfare. As a soldier, players will take their fates in their hands, battling against up to 32 other players online in an action-packed, frag-filled maps. Dispatch of Army thrust gamers in a fast-paced, bloody, action-packed combat environment as a soldier defending their country's philosophy. With the latest technology, players go against up to 32 to other players in a map. Key features of Dispatch of Army includes:  

FEAR F.E.A.R. Combat is the complete multiplayer component of F.E.A.R. and includes all the updates, additional official maps and additional official game modes all in one downloadable file. F.E.A.R. Combat users will be able to play against the owners of the retail version of F.E.A.R. as well as the other F.E.A.R. Combat users. This is a great first person shooter with excellent graphics.  

War Rock War Rock is a Free2Play tactical first person shooter (FPS) where players have the option to purchase access to a wide variety of gameplay enhancing items and services or play the game as it is without ever paying a dime. Currently in Open Beta, War Rock is populated by thousands of players at any given time in servers all over the world. With a wide variety of customizable weaponry and vehicles, intuitive controls, and multiple battle modes, War Rock is a blast for seasoned FPS veterans and first-timers alike. Join us and see why  

Survival Project A realtime online action game which you can play with other people. There are 8 different characters with different strengths and weaknesses. There are 8 different maps to play on. Give this game a try.  

Enemy Territory Originally designed as an expansion pack for Return to Castle Wolfenstein, Enemy Territory is one of the highest quality multiplayer freeware games available. There are serveral classes to choose from including covert ops, medic, soldier and field ops. There are always servers up to play on. Dont miss out! 

Grand Theft Auto Rockstar games is giving away the first and second grand theft auto games. You steal cars, police cars,tanks and complete missions. A very fun addictive game