A question!! PC players (steam) can play with PS4 players?
No, and even if we could it would be impossible for now. Console players are waiting for the new patch (already available to PC).
Ah perfect!!! Thank you!!
Yeah and at somepoint i think the devs said crossplay wasn’t something they are going to do 
Actually i will ask the same question.
Can PC players from Steam play GZ online with players who bought the same game from Humble Store or Green Man Gaming?
I have no idea i would presume so though.
I think all PC versions of GZ have to be linked to Steam, so it doesn’t matter from where you buy the game to PC.
(Correct me if I’m wrong)
There is no cross-platform play in GZ.
It was asked in one of the older dev streams and devs answer to it is at 00:29:12,
link: https://www.twitch.tv/videos/498442216?filter=archives&sort=time
Yes, as long as you register your game with serial key in Steam.
Further reading: https://support.steampowered.com/kb_article.php?ref=5414-tfbn-1352
Without registration, i’m unsure since i don’t know if Steam validation is needed to connect to Steam purchased game.
Thx for the info 
I never bought a PC game that was not physical(old guard) or from Steam store, so i was wondering about that.
I’ve purchased and acquired games from many different sources in my years. Like: physical CD (e.g Deus Ex), from Steam (most of my games), from Epic Store (Snowrunner), from developer directly (Starsector) and downloaded free from the net as well (e.g freeware games).