1) Launch your Steam application and click on Library.
2) In your games list (left hand column), Right Click on Edge of Space. That should bring up a drop menu. Select Properties (bottom option on the drop menu)
3) This will bring up the Edge of Space – Properties menu. Click on the Betas tab
4) Under drop down menu “Select the beta you would like to opt into” select “public-test”.
5) Once done, you’ll will unlock the special Multiplayer beta branch. You will be able to select it from the “select the beta you would like to opt into” drop down menu
6) Click “Close”. It should begin updating Edge of Space automatically.
7) If the update doesn’t begin automatically, click on the Local Files tab, and click Verify Integrity of Game Cache button. This will force the update.
8) Click the Play button – happy multiplayer gaming!!