
A Quake style game that features some different modes of play and instagib, cel shaded graphics and basic deathmatch style maps. Very fast paced, but a bit of a dated game style in my opinion.

A First-person shooter with great graphics and a handful of different game modes. It does require lots of resources to run well, but you can tone it down slightly to improve performance but this game is all about the graphics.

Savage: the battle for newerth is a free full game, it used to be sold but was then given away for free! The game involves 2 (or 3) teams, each having 1 “commander” which can use team resources to build structures and research upgrades for the players. Everyone else plays the game in first or third person.
Gameplay
The game is fairly easy to pick up, and your character will gain experience (exp) that provides certain upgrades like added HP or stamina, but XP is reset at the end of each game and xp does not have much of an influence on game balance. Much of the game is dictated by the decisions your commander makes, which technology tree is taken, where to expand etc. but games can suddenly swing if someone pulls a crafty move!
Graphics & performance
The game is fairly old, but is still fairly pleasing to the eye and runs surprisingly well on older hardware, turning off grass can really improve performance!
2. Spring (almost free)

Spring is an open source RTS game engine, on which people build different mods and maps. The units looks fairly basic, compared to games like Red Alert but it is truly three dimensional; you can rotate and angle the camera pretty much however you want and can even go first-person and manually control a unit. You can play against the AI opponents or you can play online via the Spring lobby.
The catch is that the most popular mod (Balanced Annihilation) requires some content from the original TotalAnnihilation, so you should own the original game if you use this content. (more info @ the FAQ).
Gameplay
The game has many tactics and counter tactics, a good amount of advanced controls; e.g. you can tell an air transport to pick up all units within one area and shuttle run them to another area, but this depth also means it’s not easy to pick up quickly. It’s even possible to draw on the ground to provide directions for your team mates, genius! There are regularly 10-12 player games, with a few 16 player games.
Graphics & Performance
The units/vehicles are quite square-looking, but recognisable. The landscapes are also quite basic, but are deformable. Most of the time the game runs fairly well, however in larger games it can really slow down and the pace of the game will be determined by the slowest person.
This is one of those games that really flys under the radar and I don’t really know why it never gets any publicity, maybe because of it’s legal reliance on the original game? Saying that, there is a regular following of players.

Quite an addictive racing game (not a simulator), a Cut-down version of Trackmania United Forever, with only 1 car but almost an unlimited number of tracks and plenty of players online.
Trackmania United Forever (TMUF) is the full-game that includes all previous Trackmania games rolled into one.
Trackmania Nations Forever (TMNF), which is free, only has the Stadium cars and tracks, however this is by far the most popular game type.
Everybody drives the same car so you don’t need to spend ages playing it to unlock better cars, the only thing you can change about you car is the appearance (TrackMania Carpark) and the sound of the horn. You can play offline in time-attack mode and attempt to beat the computer to unlock more tracks, or you can play online against others.
Gameplay
The most popular mode of play is a time-trial, the track plays for usually around 5 minutes and you must get the fastest time you can, you can restart at any time. Most tracks involve jumps, loops, and plenty of speed. There are a few servers playing race mode, where you race in real-time against others and must be the fastest to complete around 4 laps, a few of these servers run mock Formula 1 circuits. Cars are able to pass through each other so there’s no need to worry about crashing into someone else (some servers have over 100 players) but this means there’s no real over-taking as such, just passing through!
Graphics & performance
The graphics are very clean and vibrant, there are 4 different lighting conditions, and two different track surfaces (tarmac and dust). The default cars come with different decals, for each country and are fairly detailed. The game performs very well on my modest system (e6420, x1950xt, 2gb) If you do experience any slow-down you can always choose to not draw any other cars, or turn off some of the fancy graphic features.
Overall this is a great game to just pick up and instantly play, there’s plenty of people playing it and plenty of servers running different tracks.