Hey guys recently I wanted to replay this game but I noticed that there's apparently a newer version than the one on GOG. To be more precise GOG has version 1.5.1 and the steam version is 1.5.3. Is there any ETA for this new update or is it just a difference in version numbering between platforms?

It *might* be a platform-specific difference.

Patch 1.5.0 was officially released on May 21, 2017. Pirated copies of 1.5.3 surfaced as soon as May 23, 2017. The official wiki only acknowledges 1.5 and so does the game's official changelog at the Steam forums. How could a game grow three versions older over the course of just three days without any mention in any of the official sources?

They're actually releasing 1.60, now, on Steam. Has bugfixes, and some adjustments--such as allowing all achievements to be visible during freeform play.

I've asked in a thread if this is coming to GOG. Haven't heard back, yet.

Just heard from one of the development team, Joni, up on Steam, who says the 1.60 version has been forwarded to GOG. So now we just need to wait for it to go online.

Hopefully, soon.