Half-Life 2: Episode One is a shooter that continues the Half-Life series of games. After the explosion, chaos reigned in the Alliance Citadel. Gordon and Alyx escaped the released dark energy thanks to the Vortigaunts. But the reactor core is unstable, and in order to survive, the heroes need to stabilize it. The first part of the plot takes the player to the Citadel, where Freeman receives a charged gravity gun that controls organics. After connecting the protective device, the heroes go to the surface through the catacombs. There, they learn that the protective field around City 17 has collapsed.The enemies in Half-Life 2: Aftermath are varied:
- Combination soldiers - humanoids who captured the Earth within 7 hours of the invasion.
- Headcrabs - parasites from the world of Xen, capable of turning people into obedient slaves.
- Zombies - creatures infected and controlled by headcrabs.
- Barnacles - monsters that can attach themselves to the ceiling and release a long sticky tongue that absorbs all living things.
- Ant lions are insects with long, sharp paws and a large number of teeth, capable of jumping several meters in height.
- Zombines are Alliance soldiers who have fallen under the influence of headcrabs, first appearing in Half Life 2: Episode 1.
- Strider is a combat synth with heavy weapons and impenetrable armor.
In a city engulfed in flames, Gordon meets with the militia. They have captured part of the railway network and are trying to evacuate everyone they can. Under large-scale firefights with enemies, Freeman and Alyx help citizens get to the train. The arsenal of weapons consists of a pistol, machine gun, shotgun, assault rifle, crossbow, revolver and grenade launcher. In addition, the player will have the opportunity to control antlions using pheromones.