You start the game controlling the communications officer.
Reading the emails you become aware of what happened to the Atlas' crew.
These strange holograms have transmissions from an unknown source.
The map screen: from here you can command your marines.
The demolition expert firing a grenade.
The engineer reparing a broken door.
The team assembled at the start of the second mission.
There comes another mutant.
Eww, those things feast on human flesh.
The medic is following the Heavy Assault soldier.
The engineer hacks a terminal.