Unfortunately no, for some reason we couldn't implement the steam achievements on a Mac. I contacted the Renpy engine creator to have some insight but unfortunately he couldn't help either. The difference of the game on steam and here is just achievements and exposure, really. So if you just want to play the game on mac, you can only do so on itch.io
So sorry for this, if we find a workaround/renpy engine updates we will probably add Mac onto steam as well.
Hope that explains things.
Best, Xero