How to update Factorio: Space Age on your Mac

1. Let Factorio: Space Age update itself. Open Factorio: Space Age. It checks for new versions on its own, and if it has not offered one yet, look in the Factorio: Space Age menu, or under Help or its preferences, for Check for Updates, then let it download and relaunch.
2. Download the current build from the developer. Factorio: Space Age's developer publishes each release on their own site. Get the Mac build from there.
3. Replace the old copy. Quit Factorio: Space Age, open the download and put the new Factorio: Space Age in Applications in place of the old one: a disk image is dragged across, an installer package runs its own steps. Your settings and documents live outside the app and are kept.

That is one app. The same walk, through a different menu or page each time, is what every other app on the Mac asks of you, which is where Floodtide comes in.

Floodtide's own signed catalog lists where Factorio: Space Age's developer publishes each release, and Floodtide reads that source directly to learn which version is current. When yours is behind, the row appears under Updates with the version that is out, next to every other app on the Mac that is behind.

The developer publishes the version but no download Floodtide can check, so Floodtide does not install this one itself. The update comes from Factorio: Space Age's own updater, or from the developer's site, and Floodtide is what tells you the day it is due.