Way to make it impossible to know that the Victor OpenDev isn't available to Mac unless you find the super fine print (in one location as far as I can tell, and only when you're troubleshooting why it's not working).  In all the leader info it says Victor OpenDev available to ALL STEAM CUSTOMERS WHO PREORDER.  Super job at getting my money 4 months early.  If I can get a refund, not sure I'll buy this game at all now, given the deception.  Effing ridiculous.

As someone gaming on a Mac you should already be used to checking these things in advance, and you really don't even have to look far deeper than just googling the game...

Compared to a game that does support MacOS:

I understand your frustration though, it's a pain looking forward to a game this much only to find out that it's not even available on your platform. However since it runs on Unity, they have said that Mac is very likely to be usable in the future too. 

Macintosh Operating System is MacOs

Final game will be compatible MacOs but the steam page states openDev is windows only

But indeed they shouldn't say it is availalbe to everybody who preordered on Steam (even though it is technicially as the purchase of the game is for any version you also have the windows version) as it can be misleading wihouth adding its windows only

Also the pre order isnt necessary to have access to openDev, it is just a way to avoid having to watch 3h of Twitch streams