I'm afraid that hitting Enter to start did nothing in Chromium, and I couldn't even get that far in Firefox. It sounds as though other people have had more luck than I did, though, so hopefully you get plenty of ratings - what I did see looked pretty polished for a jam game!
Viewing post in Cosmic Exodus: Echoes of A Lost World jam comments
Please open it using, google or microsoft edge. Also you can try on this link: https://gd.games/erdogantaskurt/cosmicexodus