I've just updated GOG and now I can't find the option to just play Theme Hospital, it's only giving me the option to Install. If i install now I'll lose all i've done on the game. I'm on the last level!! HELP!

Yeah, it just auto-updated me to the galaxy beta, and has lost 5 games. I will try and play around now to find a solution to our troubles. The games are still there in your folder, it's just a matter of helping GOG Galaxy find them...

EDIT: Actually, after a few minutes it seemed to find them. If yours are still missing there's an option "Scan and import games" in the settings menu, could be worth a try...

So the phasing (p)out of Galaxy v1.x has started in earnest.

Yes, um phasing out. I was told an update was available, clicked "Remind me later" restarted galaxy and it's updated! More of a cull than a phasing.

Errm, hello Galaxy specific forum:
https://www.gog.com/forum/general_beta_gog_galaxy_2.0#1588186800

If galaxy doesn't work, delete it. Come to the light side!

He had no idea what galaxy was. He refered to it as GOG. It was a forced update, not a beta issue.