Same problem. Just bought the game via Steam, that has been out since Jul 28th 2020.
Clicking play cause screen to flicker for an instant (so fast the play button doesn't have time to change to 'running' visually) and nothing.
I decided to browse the local files and run 'Grounded.exe' directly as an Administrator.
Yields the following error:
Main-Win64-Shipping.exe - Entry Point Not Found
"The procedure entry point EventSetInformation could not be located in the dynamic link library ADVAPI32.dll"
I searched all sub-folders of the steam install directory. I could not locate this file there. Maybe that's why it can't find the entry point?
I have also sent a message via the portal, got the reply email. I'd give you a ticket or reference number, but your response email contains none.
edit2: I just discovered I bought this once 5 months ago. It was doing the same thing and had to refund it. FIVE MONTHS later, and it's still doing the same thing? This speaks volumes and I've updated my curator review to reflect this lapse in fixing something 5 months old that prevents someone from even launching the game, let alone playing it.