It's all good to go, folks... Launch happened yesterday. I pre-ordered this game over 5 years ago, and it was worth the wait.
Think Starcraft or Warcraft (1 2 or 3) where the minions and units are all real people. Aliens versus marines in a fight over a mining colony.
As the aliens take over the map, their biological "infestation" begins to cover the walls and floors. The marines must fight this back, along with the aliens, to be able to control resource nodes needed for researching and creating weapons and equipment.
Play as a marine with options for jetpack and exosuits, and weapons from MG, shotgun, grenade launcher and flamethrower. Play as alien and be a "skulk" that can climb on walls and ceilings, leaps and bites, a "lerk" who flies and bites, and shoots spikes or poison gas, a "fade" who kind of teleports or phasewalks and slashes, an "Onos" which is the giant rhino and can stomp the ground knocking over nearby marines or the "Gorge" who builds and heals, and has a spit that erodes marine structures.
Then there's the commander for each team who gets a top-down view, decides the research path to use and provides orders and support to the team.