Unfortunately Catalina changed quite a lot of things in the backend, dropped 32bit support but most troublesome now developers have to go through a costly notarization process for their apps to run. I don't have a Mac so that makes the process impossible without resorting to a porting house or a third party to sign my apps. So unfortunately I don't think I'll be able to support Mac anymore for the time being :( 

edit: def reccomend installing a small bootcamp partition tho with Win10 in the meantime if you want to try more itch games that are not supported :)