Deathmatch is the only competitive campaign included in Alien Swarm: Reactive Drop. Unlike the other campaigns, missions in this campaign do not have conventional objectives - rather, a win condition is set based on the type of Deathmatch chosen.
Kill everything that moves.
- Killing an alien doesn't count for your score.
- Aliens can spawn on the first and the second map when Onslaught Mode is activated.
- Several sound effect are taken from other video games.