If Mac game developers miss these settings, their brand new game for Apple Silicon will be listed as unplayable on anything after macOS 10.15 Catalina. Here’s how to tell Steam that your game is compatible, and where the flags are.

Steam’s macOS Catalina warning
Valve Software’s gaming storefront, Steam, is the biggest of its kind when it comes to PC and Mac gaming. It is essential for any game developer targeting those platforms to put a build on Steam, due to the sheer size of its audience.
However, while Steam is relatively simple for gamers to use, the back-end is considerably more complex. For a developer starting out, there are many things that can be missed when putting their game onto Steam for the first time.
