Source-backed guide · Updated 2026-07-18

How to Play Pathogenic Co-op with Remote Play Together

Set up Pathogenic local co-op or invite a remote player through Steam Remote Play Together using the Diatom Pathogen.

Published by Pathogenic Game Wiki Editorial Team · Updated 2026-07-18

Quick answer

Pathogenic supports local co-op, not native online multiplayer. A remote second player can join through Steam Remote Play Together, and the Diatom is designed for two-player control.

Remote Play Together setup

  1. 1.The host launches Pathogenic through Steam.
  2. 2.The second player signs in to Steam.
  3. 3.The host presses Shift+Tab to open the Steam Overlay.
  4. 4.In the Friends List, the host right-clicks the friend and selects Remote Play Together.
  5. 5.The friend accepts the invitation and joins the streamed local session.
  6. 6.Select the Diatom when the co-op option is available; each player controls one half.

Important limitation

Remote Play Together streams the host’s local co-op session. It is not a dedicated online mode, so the host’s connection and input setup affect the experience.