Command & Conquer 4: Tiberian Twilight

Summary pulled directly from Steam - Some text may only be applicable to Steam platform

It is the year 2062 and humanity is at the brink of extinction. Tiberium, the mysterious, alien crystalline structure that has infested Earth for decades and served as the primary reason for years of relentless conflict between the Global Defense Initiative and the Brotherhood of Nod, is close to rendering the planet uninhabitable. Mankind is on the verge of extinction when Kane, Nod’s prophetic leader, emerges from seclusion to deliver GDI the message that he has developed a system that could control Tiberium and harness its power.

The Spoils of War - The more enemies you destroy, the more experience points you earn for upgrading your faction and unlocking powerful new weapons.
Choose Your Class - Command more units than in any other Command & Conquer game! Choose the Offense, Defense, or Support class, each with its own specialized units and powers to match your style of play.
Always on the Move - Introducing the Crawler, your all-in-one mobile base. Pack up and redeploy across the battlefield for a new layer of strategic depth.