Hi!
Sadly macOS is quite problematic system to make builds for, especially if you don’t own a mac.
However, you may be able to run the game on macOS:
There is an older build of INSTEAD available: https://github.com/instead-hub/instead/releases/download/3.5.1/Instead-3.5.1.dmg
It’s only x86_64, but should work on ARM macs. The app is not signed, so you will need to follow these steps: https://support.apple.com/guide/mac-help/open-a-mac-app-from-an-unknown-developer-mh40616/mac
Now to running the game:
Download the game package for other platforms. Do not unpack the zip.
Run INSTEAD, press esc to open menu and choose “Select Game”, “[…]”. Choose the game’s zip file.
If the game does not fit the screen, press esc to open menu and choose “Settings”, “Graphics” and adjust “Resolution” or set “Full screen” to “On”.
I’ll add these instructions to my website and link them here, but please note that we may not be able to help you with any macOS-specific issues with the game or the engine.