Orion's Threat, included in Alien Swarm: Reactive Drop, was formerly the only campaign for which it was impossible to acquire all campaign-specific achievements. However, the first post-release update fixed the impossible achievements, and they can now be earned.

Story Edit

Stop an Alien Swarm!

Missions Edit

Niosa Refinery Edit

  • Destroy Swarm Eggs 0/23
  • Redirect power
  • Recieve [sic] Code
  • Proceed deeper inside the facility

First Anomaly Edit

  • Destroy Swarm Eggs 0/18
  • Access the industrial complex

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