Quake 4 SDK description
In a desperate war for Earth's survival against an unrelenting alien enemy, the only way to defeat them is to become one of them

Earth is under siege by the Strogg, a barbaric alien race moving through the universe consuming, recycling and annihilating any civilization in their path. In a desperate attempt to survive, an armada of Earth’s finest warriors is sent to take the battle to the Strogg home planet.

You are Matthew Kane, an elite member of Rhino Squad and Earth's valiant invasion force. Fight alone, with your squad, or in hover tanks and mechanized walkers as you engage in a heroic mission to the heart of the Strogg war machine.

Battle through the beginning of the game as a combat marine, then after your capture, as a marine-turned-Strogg with enhanced abilities and the power to turn the tide of the war.

Built on id Software's revolutionary DOOM 3 technology, QUAKE 4 also features fast-paced multiplayer competition modeled after the speed, feel, and style of QUAKE III Arena.

Here are some key features of "Quake 4":

· Highly anticipated sequel to id software's award-winning QUAKE II.
· Diversity of combat. Fight through solo missions as well as buddy and squad-based operations; or pilot heavy walkers and hover tanks through outdoor battles and epic firefights.
· Being captured and converted to Strogg becomes Earth's only hope for defeating the Strogg.
· Player is not alone – he and his squad are part of a massive invasion force.
· Utilizes the industry leading DOOM 3 technology to create an unparalleled visual and aural experience.
· Arena-style multiplayer that allows players to play as Strogg or Marine in deathmatch, team deathmatch and capture-the-flag modes.