HypersomniacLive: Changelog for Update 1 (added 21 November 2017):

* Fixed an issue where screenshots would sometimes not be saved when using the Camera Badge
* Added the option to turn off camera shake
* Resolved issues with the camera where it would on occasion flip out while in tight corridors
* Fixed some regional PS4 controllers not being recognized by the game
* Fixed interact button not showing up as the circle button with a PS4 controller
* Fixed jigglebones twitching when running at low framerates
* New camera filter: Silhouette
* Improved issue where camera would continuously bump against ceilings when in tight corridors.
* Fixed credits sometimes not fading out.
* Fixed Kid's Hat pointing to already collected Time Pieces if a non-collected Time Piece is available.
* Further preparation for Modding Support release (coming soon!)
* Added an ingame remix of Your Contract Has Expired
* Fixed a visual issue with the scooter sometimes turning sideways and sinking through the floor
* Fixed a softlock in the Twilight Bell when opening the metal gate with the fox mask
* Updated a selection of Time Rift photos
* Fixed Blue Vault dropping content into lava in lava version of Mafia Town
* Performance improvements in the Subcon Cave Rift & Mafia Cave Rift
* Fixed the Picture Perfect remix being available before Picture Perfect becomes available
* Minor camera improvements to hallways & tunnels in Dead Bird Studio (and its secret area)
* Fixed incorrect icons on the Dweller Mask flairs
* a good boy added to credits
* Improved the speedrun timer
* Fixed alpha issue on Hat Kid's face in Mafia HQ cutscene
* Gallery time rift camera fix
* Removed rift token in Chapter 5 that falls into the abyss

MemoryDreams: Strange thing, I still can't make screenshots via that badge. To be honest, I didn't see any changes what so ever. It's ashame. Although I've seen some undates in GOG Galaxy. I even tried 'repair'-button. Oh well...

MemoryDreams: Is everything alright with your game?

MemoryDreams: Couldn't you, by any chance, have posted changelog for Steam version?

HypersomniacLive: I post the changelogs as they're made available here on GOG. You can find the update history of every owned game that ever got a changelog by visiting your game library via your browser, open the game card of a game (A Hat in Time for instance), then click on More>Changelog.

Having said that, changelogs are provided by the devs/pubs. If they contain features and fixes not available in the GOG version of the game, the responsibility for the changelog being representative of the GOG version falls on the devs/pubs and GOG. Which in turn brings us, again, to contacting GOG Support to clear this up, or get technical help in case everything mentioned in Update 1 is accurate.

Hope this helps a bit as there's nothing more I can say or do, sorry.

MemoryDreams: Strange thing, I still can't make screenshots via that badge. To be honest, I didn't see any changes what so ever. It's ashame. Although I've seen some undates in GOG Galaxy. I even tried 'repair'-button. Oh well...

mmodri: New update

Update 2 (05 April 2018)
Camera calculations have been optimized significantly, providing a performance boost on the CPU
Minor performance improvements to rendering, providing a minor performance boost on the CPU
Fixed a bug where flairs would appear incorrectly in certain cutscenes
Updated the Korean fan-translation
Fixed balloons appearing bright in night time version of Mafia Town
Fixed collision in a few spots in Murder on the Owl Express
Editor: Fixed crash relating to CubeMaps
Editor: Static Mesh Editor now has a turntable option, in case you like seeing models spin around... very fancy!