Zero-K is a FREE, multi-platform, open source Real Time Strategy game, which aims to be a dynamic, action-packed, hassle-free experience, full of clever strategies and constantly moving combat. Includes an epic scale, realistic projectile and unit physics, terraforming terrain and hundreds of unique and interesting units.

nicemonkey says

10/10 - Agree (1) Disagree (1)

Zero-K is one of my favorite RTS games. It has a bit of a learning curve but after you master the basics the gameplay is excellent.