I may have put a post about this in a previous thread. But I decided to make a thread about it to try and bring more attention to it.
This game is called Warzone 2100. It is an RTS that is old but it is severely underrated. It is a game made by Eidos that was originally put on the PS1. There is a group that have started a Revival Project of the game and making it playable on the PC. This is FREE. It also includes a Singleplayer campaign that even teaches you everything that can be done in the multiplayer. Another challenging aspect to this game is that in multiplayer you dont start with premade designs for offensive units. You actually have to DESIGN your own offensive units by researching the turrets.
Here are a couple of screenshots (graphics aren't as great as most are now. remember this game was originally made in the 90s)
(the graphics in the first pic are blurred cus i had to stretch the photo to make it fit the post.)
System Requirements:
At least 1 GHz CPU
At least 128 MB VRAM
OpenGL 1.4 (make sure you have the latest drivers installed)
At least 100 MB free RAM for the game
At least 100 MB HD space for the game, up to 600 MB extra for the standard videos
Official website: http://www.wz2100.net
Virus Free! Just not that well-known. Enjoy!!