At a glance
Kingdom: Classic has a Mac version: Steam sells it for macOS. Install it in Steam for Mac; it doesn’t need Uncork. The requirements explicitly say Apple Silicon is not supported.
Kingdom: Classic came out on Steam on 21 October 2015, made by Noio, Licorice.
What your Mac needs
Minimum macOS in the Steam requirements: 10.6.
Steam requirements list at least 2 GB of memory for Kingdom: Classic; 4 GB recommended.
Allow about 0.512 GB of disk space for the Mac version.
How to play
Open Steam for Mac and install Kingdom: Classic as usual.
If the Mac version will not start, you can install the Windows version through Uncork: download Uncork, sign in to Steam and install Kingdom: Classic from there (0.512 GB). We have not tested it ourselves.
The Windows version through Uncork needs a Mac with Apple Silicon (M1 or newer).
Kingdom: Classic uses DirectX 9.0c: Uncork renders it with its built-in graphics.