Mankind spread out into the stars, but ran into a hostile race of arthropods with a hive mentality. You play as a space marine, and your job is to eliminate alien hives from various planets that the human military targets.
Deliver a nuclear warhead to the bottom of the hive and detonate it. Don’t worry, we’ll beam you out of the hive before the nuke goes off… if you live that long. You and your squad will descend down a (procedurally generated) alien hive while fighting off all manner of insect aliens, avoiding traps and hazards, and collecting resources when appropriate (gotta fund that military expansion somehow). One member of your squad has a translocator beacon backpack, this allows us to beam down reinforcements to your location within the hive, whether this be more men (respawn), weapons (bought with resources gathered, or found on dead marines), or the final nuclear payload used to destroy the hive.
If the squad member with the backpack dies, the other marines must pick up the backpack (also the camera view stays around the backpack). If there are no members of your squad left to protect the backpack, the aliens will rip it to shreds and we’ll have to assault the hive from the surface again. (There are respawn/teleport timers, so players who die have to wait a while before they’re back in, if everyone is dead and on their timer, you lose.)
Once you reach the bottom of the hive, you enter the queen chamber. The queen is a boss that summons many types of aliens to her aid, and uses a few area-denying acid-spit moves herself. Once you reach the queen’s hive room, she lets out a cry that blocks your escape back upwards. Luckily, you have your translocator backpack, the nuke is teleported in and a countdown begins until detonation.
You, brave marine, must guard the nuke from destruction by the aliens until it is about to detonate, then we will beam you out.