is the Cross play possible for it and if how?

What do you mean by cross play? If you mean local coop via split screen - it is announced and will be available in a later update.

the GOG Galaxy, Cross play feature

wich should enable multiplayer whit steam users

This would be highly interesting for me too. Anyone tried it yet?

You can play with Steam users just by logging inside the game and invite your friends to your game, you just need to know their account name in VV. :)

Edit: to be more precise, the procedure to add a user to your friend list is somewhat annoying, you need to be in the same chat room, then go at the room user list, scroll down to your friend nickname, and click it selecting "add to friends". AFAIK there's no direct way to add a Friend from the Friend menu, sadly.

Hi papa

wow this is such a wow that we get to do

That's really neat