Warsow

Site: http://www.warsow.net/
Status: Free

Warsow is an open-source, online FPS. The game is centered more at the gameplay and less at the graphics. The graphics are made intentionally plain and clear. The gameworld is the meeting point of the cartoon characters with the cyberpunk city.

Gameplay
Warsow is fast and when I say fast I mean really fast. New players may have difficulties at the beginning. Even veteran FPS players need some time to grasp the style and the speed. Despite that fact, the game is quite fun with many adrenaline bursts and hearth beat situations.
Online players tend to be way too good and merciless for newcomers like me. Combining series of movements and jumps with the fast speed of the game brings unique experience and excitement.

My rating: 9 from 10.
If you are Quake series fan, you will like this one too!

How-to play
Simply download the game from the official website - http://www.warsow.net/?page=download. It is available for Windows, Linux and Mac OS X.

Warsow official trailer:


Screenshots:

Daimonin Review

Site: http://www.daimonin.org/

Daimonin is an open-source, 2D, isometric MMORPG. Here is the project page at sourceforge - http://sourceforge.net/projects/daimonin/files/Experimental/.
You can try the game on a free public server at the official website or download the client and the server and run them.
Daimonin offers vast world with many quests, races and genders. The game features large number of quests.
You can download map editor and create your own maps.

Screenshots

 

 

Eternal Lands

Site: http://www.eternal-lands.com/

Eternal Lands is a free MMORPG game under development. It is not so well-known mainly because it is not developed by some large and multinational game development company but a small team.

I really enjoy this type of games – they are not so perfectly working but you can touch part of the game development process. You can visit the developers page and the forum to learn more.

In EL characters are not bond to a profession, they can learn any skill they like and change it anytime. Players can choose between six playable races: humans, elves, dwarves, gnomes, orchans and draegoni. I didn’t find much visual difference between the races though.

OpenAnno - open source real time economy simulation game

Site: http://openanno.org

OpenAnno is an open source project, aiming to create 2D real time economy simulation strategy game. It is using the FIFE game engine(http://www.fifengine.de/).

PlaneShift

Official Site: http://www.planeshift.it/
PlaneShift is a fantasy open-source MMORPG in development.
Screenshots:

PlaneShift Trailer Video:

The Mana World

Site: http://themanaworld.org
Download: http://themanaworld.org/downloads.php
Wiki: http://wiki.themanaworld.org
Current Version: 0.0.24

The Mana World is an open source free 2D MMORPG in development. It is intended to became nice place for community meetings and fun.
Anyone can join the project and experience creating a MMORPG game. For more details how to make this visit http://wiki.themanaworld.org/index.php/Joining_the_project