We've officially launched the MacOS version of the game on STEAM. If you already have the game installed via STEAM, you should be able to download and play it.
In case you encounter an error about Apple Developer ID, please look into this quick fix:
https://herculion.zendesk.com/hc/en-us/articles/900000229363-Troubleshooting-MacOS-error-Game-is-not-signed-by-an-Apple-Developer-
A minor fix included in this fix is the replacement of Lenga's CG during the Costume Party. This is by request of his original character artist, lvlv.
If you encounter any other troubles, please contact us via our help desk: https://herculion.zendesk.com/hc/en-us