Hi Tythor, it looks like a DLL is missing. Are you able to open the Celeste app with Finder and look inside Celeste.app/Contents/MacOS/osx and see if "libmojoshader.dylib" is there?
I have no clue what fixed it, but I tried launching the game this morning, and it started up perfectly fine. I had a feeling the issue was specific to my computer since I couldn't find anyone having similar problems online. Sorry for the trouble, and thanks for the amazing game Noel!
