At a glance
Celeste has a Mac version: Steam sells it for macOS. The Mac requirements list only Intel: on Apple Silicon Rosetta 2 runs it, and old Mac versions sometimes do not start on current macOS. Try it in Steam for Mac first.
Celeste came out on Steam on 25 January 2018, made by Maddy Makes Games Inc., Extremely OK Games, Ltd.
What your Mac needs
The Mac requirements list only Intel.
Minimum macOS in the Steam requirements: 10.7.5.
Steam requirements list at least 2 GB of memory for Celeste.
Allow about 1.2 GB of disk space for the Mac version.
How to play
Open Steam for Mac and install Celeste 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 Celeste from there (1.2 GB). We have not tested it ourselves.
The Windows version through Uncork needs a Mac with Apple Silicon (M1 or newer).
Celeste uses DirectX 10: Uncork renders it with D3DMetal.