Hello,
Sometimes there will be a NW.js screen if the game's files have been separated, so please make sure to keep them all together as downloaded and not drag anything out of the folder. Multiple users have been having problems with the Mac version here, but I can't seem to find those topics anymore. Usually, it's resolved when they redeem the game on Steam. In the future, I plan to make Mac versions of my new games on Steam only, as there appear to be fewer issues when installed through their launcher, and you can quickly get a refund through their system if it doesn't work after all.