Hey, did you extract the folder named 'Rotund Dungeon' from the .zip? Unity games wont run inside an archived folder. If it's not that get back to me and I'll see what I can do to help!
Thanks for fixing this, it’s a fun game!
FYI the executable inside the app doesn’t have execute permission for some reason. For anyone else who wants to run on mac, run this before opening: chmod a+x ~/Downloads/Rotund\ Dungeon\ (Mac\ Build).app/Contents/MacOS/ROTUND\ DUNGEON (or wherever the app is)