The closest matches on Steam are EARTH DEFENSE FORCE 5, EARTH DEFENSE FORCE 4.1 The Shadow of New Despair, Starship Troopers: Extermination, Sven Co-op and Left 4 Dead 2.
From the Steam games with at least 2,000 reviews and 80% or more positive, we keep the ones whose main player tags match Alien Swarm's most closely, then show the closest first.
