The story in HL2 is a mess. You go from city controlled by invaders to zombie town to "They" town to nonsense alien citadel. They all have absolutely nothing to

The story in HL2 is a mess. You go from city controlled by invaders to zombie town to "They" town to nonsense alien citadel. They all have absolutely nothing to do with each other, they're just glued together because some designers/artists thought it would be cool to have them. Players fill in the rest with their own imagination, not by any smart writing or design by Valve.