Thanks for clarifying. I can safely delete my old installer then... right? :-)

If there are large differences in version number and file size like in this case, a changelog should really be provided, even if it only is to mention that the game itself didn't change and only the setup has better compression.

Transparency is good for customer care!

For minor changes which may not matter to us I would expect that one of the last digits in the version number changes, but not the second most significant one (like it happened with Freedom Force or Psychonauts). And then there's also the doubt if someone on GOG just forgot to add the changelog entry or if it's really a change which does not matter.

So eventually it may even be less work for GOG to add a proper changelog entry instead of reading and answering lots of questions related to an update. ;)

Edit: So I assume the last update of the Psychonauts installer also has been a minor change and does not matter to us, right?

Huh...

From MaGog's logs for 12 February (part 1 of 2):

NOTE! Probably CHANGED FILE Darkest Dungeon, all_files, Windows installer, English, dl_ver: 13488 (gog-10) ***TO*** 13544 (gog-11)

NOTE! Probably REMOVED FILE Darkest Dungeon, all_files, Patch 13407 (gog-7) [Windows] (dl_ver: 13377 (gog-6) -> 13407 (gog-7))

NOTE! Probably ADDED FILE Darkest Dungeon, all_files, Patch 13544 (gog-11) [Windows], dl_ver: ***TO*** 13488 (gog-10) -> 13544 (gog-11)

NOTE! Probably CHANGED FILE Darkest Dungeon, all_files, Mac OS X installer, English, dl_ver: 13488 (gog-11) ***TO*** 13544 (gog-12)

NOTE! CHANGED Darkest Dungeon, changelog (http://www.an-ovel.com/downloads/chg/chg_1450711444.htm)
NOTE! ADD +++ Patch 13544 (12 February 2016)
NOTE! ADD +++ New Icons for OS X and PC
NOTE! ADD +++ Misc Save Fixes
NOTE! ADD +++ Fixed a crash when starting a dungeon.
NOTE! ADD +++ Fix to activity log showing random trinket when gambling and gaining a trinket.
NOTE! ADD +++ Updated SDL Library to improve application stability





NOTE! CHANGED FILE Symphony, downloadables, Windows installer, English (setup_symphony_2.2.0.13.exe ***TO*** setup_symphony_2.3.0.14.exe; 1473 (gog-13) ***TO*** 1481 (gog-14); Mon, 28 Dec 2015 13:59:56 GMT ***TO*** Fri, 12 Feb 2016 11:31:13 GMT; 341,139,392 ***TO*** 341,170,680)

NOTE! CHANGED Symphony, changelog (http://www.an-ovel.com/downloads/chg/chg_1207659079.htm)
NOTE! ADD +++ Patch 1481 (12 February 2016)
NOTE! ADD +++ This update contains a critical fix for AAC/M4A file support.





NOTE! CHANGED FILE Train Fever, downloadables, Windows installer, English (setup_train_fever_2.2.1.5.exe ***TO*** setup_train_fever_2.3.0.6.exe; 6219 (gog-5) ***TO*** 7554 (gog-6); Mon, 21 Sep 2015 08:27:35 GMT ***TO*** Fri, 12 Feb 2016 11:53:53 GMT; 1,610,387,336 ***TO*** 1,613,725,576)

NOTE! ADDED FILE Train Fever, downloadables, Patch 7554 (patch_train_fever_2.3.0.6.exe; 7554 (gog-6); Fri, 12 Feb 2016 11:50:30 GMT; 12,401,504)

NOTE! CHANGED FILE Train Fever, downloadables, Mac OS X installer, English (train_fever_2.3.0.9.dmg ***TO*** train_fever_2.4.0.11.dmg; 6219 (gog-9) ***TO*** 7554 (gog-11); Thu, 17 Sep 2015 09:32:03 GMT ***TO*** Fri, 12 Feb 2016 11:55:04 GMT; 2,136,102,812 ***TO*** 2,141,341,141)

NOTE! CHANGED FILE Train Fever, downloadables, Linux installer, English (gog_train_fever_2.3.0.6.sh ***TO*** gog_train_fever_2.4.0.7.sh; 6219 (gog-6) ***TO*** 7554 (gog-7); Thu, 17 Sep 2015 09:34:02 GMT ***TO*** Fri, 12 Feb 2016 11:55:35 GMT; 2,147,691,915 ***TO*** 2,152,620,936)

NOTE! ADDED FILE Train Fever, downloadables, Patch 7554 [Linux] (patch_train_fever_2.3.4.7.sh; 7554 (gog-7); Fri, 12 Feb 2016 11:51:09 GMT; 8,186,816)

NOTE! CHANGED Train Fever, changelog (http://www.an-ovel.com/downloads/chg/chg_1424258777.htm)
NOTE! ADD +++ Patch 7554 (12 February 2016)
NOTE! ADD +++ Added height map import feature (play height maps instead of random maps)
NOTE! ADD +++ Added terrain asset placement tools (both free placement and track-aligned assets)
NOTE! ADD +++ Added tram catenary feature (tram tracks can be electrified)
NOTE! ADD +++ Added “maxTownSize” as a base config parameter to limit maximal town size
NOTE! ADD +++ Added Swedish translation
NOTE! ADD +++ Improved train behavior (trains no longer reverse when tracks are demolished)
NOTE! ADD +++ Improved train behavior (trains no longer reverse when stations are (un)-grouped)
NOTE! ADD +++ Improved industry grow / decline behavior (faster growth, slower decline)
NOTE! ADD +++ Improved track, road, and station construction (Shift key disables snapping and - enables precise rotation)
NOTE! ADD +++ Improved auto replacement tool (locomotives can also be placed at the end of a train)
NOTE! ADD +++ Improved bulldozer tool (trees and assets bulldoze support)
NOTE! ADD +++ Improved Intel Graphics compatibility (note “intelGraphicsMode” in settings.lua)
NOTE! ADD +++ Improved vehicle “no path” warning (now a hint that electricity may be needed is displayed)
NOTE! ADD +++ Improved modding support (Lua config scripts get no longer overridden by other mods)
NOTE! ADD +++ Improved modding support (added file filters: “bridge”, “tunnel”, “railroadCrossing”, “trainStation”)
NOTE! ADD +++ Improved modding support (added “scenario” button to advanced game settings, sets filters above plus “model/other”)
NOTE! ADD +++ Improved modding support (scripts of mods/DLCs can now access GUI selection)
NOTE! ADD +++ Improved modding support (DLCs and mods can now overwrite the built-in shaders)
NOTE! ADD +++ Improved modding support (added "1520" to list of known DLCs)
NOTE! ADD +++ Improved late-game performance (less/shorter end-of-month freezes)
NOTE! ADD +++ Improved localization (all translations have been updated)
NOTE! ADD +++ Fixed Donnerbuechse model missing texture
NOTE! ADD +++ Fixed a bug which caused incorrect town building collisions
NOTE! ADD +++ Fixed a rare bug that caused save games to not load
NOTE! ADD +++ Fixed a rare train movement crash

NOTE! CHANGED Train Fever, languages: Text only: Chinese, Czech, German, English, Spanish, French, Hungarian, Italian, Japanese, Korean, Dutch, Norwegian, Polish, Russian ***TO*** Text only: Chinese, Czech, German, English, Spanish, French, Hungarian, Italian, Japanese, Korean, Dutch, Norwegian, Polish, Russian, Swedish

NOTE! CHANGED Train Fever, file_size: 1.5 GB ***TO*** 1.6 GB

From MaGog's logs for 12 February (part 2 of 2):

NOTE! Probably CHANGED FILE Valhalla Hills, all_files, Original Game: Windows installer, English, dl_ver: 1.02.00 (gog-3) ***TO*** 1.04.07 (gog-4)

NOTE! Probably REMOVED FILE Valhalla Hills, all_files, Patch 1.02.00 [Windows]

NOTE! Probably CHANGED FILE Valhalla Hills, all_files, Original Game: Mac OS X installer, English, dl_ver: 1.02.00 (gog-4) ***TO*** 1.04.07 (gog-8)

NOTE! Probably CHANGED FILE Valhalla Hills, all_files, Original Game: Linux installer, English, dl_ver: 1.02.00 (gog-2) ***TO*** 1.04.07 (gog-3)

NOTE! Probably REMOVED FILE Valhalla Hills, all_files, DLC: Two-Horned Helmet In-Game Items: Windows installer, English (dl_ver: 1.02.00 (gog-2))

NOTE! Probably REMOVED FILE Valhalla Hills, all_files, DLC: Two-Horned Helmet In-Game Items: Mac OS X installer, English (dl_ver: 1.02.00 (gog-4))

NOTE! Probably REMOVED FILE Valhalla Hills, all_files, DLC: Two-Horned Helmet In-Game Items: Linux installer, English (dl_ver: 1.02.00 (gog-1))

NOTE! Probably ADDED FILE Valhalla Hills, all_files, DLC: Sands of the Damned DLC & Two-Horned Helmet In-Game Items: Windows installer, English, dl_ver: ***TO*** 1.04.07 (gog-4)

NOTE! Probably ADDED FILE Valhalla Hills, all_files, DLC: Sands of the Damned DLC & Two-Horned Helmet In-Game Items: Mac OS X installer, English, dl_ver: ***TO*** 1.04.07 (gog-4)

NOTE! Probably ADDED FILE Valhalla Hills, all_files, DLC: Sands of the Damned DLC & Two-Horned Helmet In-Game Items: Linux installer, English, dl_ver: ***TO*** 1.04.07 (gog-2)

NOTE! CHANGED Valhalla Hills, changelog (http://www.an-ovel.com/downloads/chg/chg_1445528240.htm)
NOTE! ADD +++ Patch 1.04.03 (12 February 2016)
NOTE! ADD +++ Dwellings
NOTE! ADD +++ Dwellings have been overhauled. They now have room for considerably more
NOTE! ADD +++ Vikings, but the radius of the small buildings has been decreased. The largest
NOTE! ADD +++ dwelling's radius is much bigger. Now every Viking working near a dwelling has a
NOTE! ADD +++ place to sleep.
NOTE! ADD +++ Dwellings now indicate the current and maximum capacity of residents.
NOTE! ADD +++
NOTE! ADD +++ UI
NOTE! ADD +++ Military camps now display how many and which fighters are assigned to them.
NOTE! ADD +++ Signposts in front of buildings: You can now instantly see how many workers are
NOTE! ADD +++ assigned to a building (corresponding number of signs) and if they have the
NOTE! ADD +++ necessary tools.
NOTE! ADD +++ Pause mode is now better indicated and the UI is deactivated during pause mode.
NOTE! ADD +++ The active profile is now highlighted.
NOTE! ADD +++ Upon winning a game, detailed statistics about the match will be displayed.
NOTE! ADD +++ You can now build roads leading from and to buildings by directly clicking the
NOTE! ADD +++ building in road-construction mode.
NOTE! ADD +++
NOTE! ADD +++ Vikings
NOTE! ADD +++ Idle fighters will try to support their brothers in arms.
NOTE! ADD +++ You can now place wells only where water is in the ground.
NOTE! ADD +++ New goods: Bones, bone axe, bone bow, bone spear. Animals will now drop leather
NOTE! ADD +++ and bones in addition to meat. You can now build weapons from these materials.
NOTE! ADD +++
NOTE! ADD +++ Odds & Ends
NOTE! ADD +++ Problem solved where the game started to slow down at some point.
NOTE! ADD +++ An issue with calculating visibility of worn items in mist has been solved.
NOTE! ADD +++ -Two issues causing crashes have been fixed.
NOTE! ADD +++
NOTE! ADD +++ Patch 1.03.03 (12 February 2016)
NOTE! ADD +++ Flat Lands
NOTE! ADD +++ We have a new type of mountain: "normal (flat)". It’s, well, much flatter. That
NOTE! ADD +++ means more water surfaces and less locations where rock is visible.
NOTE! ADD +++ This type of mountain can be selected at the start of a game.
NOTE! ADD +++ Upon creating a new map the seed can be manually entered. Seed, type of
NOTE! ADD +++ mountain and size can be passed on to friends enabling them to play the same
NOTE! ADD +++ map.
NOTE! ADD +++
NOTE! ADD +++ Vikings
NOTE! ADD +++ Kitchen: "resources" for sandwiches are now blocked and can’t be consumed
NOTE! ADD +++ directly. In an emergency the building can be switched off - this frees the resources.
NOTE! ADD +++ The kitchen is no longer prioritized. Berries and mushrooms are no longer stored
NOTE! ADD +++ in the kitchen.
NOTE! ADD +++ Vikings act more sensible as a group: If more than one Viking targets a resource,
NOTE! ADD +++ the first worker there will inform the others to search elsewhere.
NOTE! ADD +++ Millers and farmers now work even if they are hungry.
NOTE! ADD +++ We have new and better tools for hunters and couriers. Hunters get stronger,
NOTE! ADD +++ couriers can carry more wares.
NOTE! ADD +++
NOTE! ADD +++ Couriers
NOTE! ADD +++ Couriers now deliver to storage buildings.
NOTE! ADD +++ Couriers now deliver directly to construction sites.
NOTE! ADD +++
NOTE! ADD +++ UI - building
NOTE! ADD +++ The current stock of building materials is shown in the building menu.
NOTE! ADD +++ When you’re building, a preview of the building will be shown at the mouse cursor.
NOTE! ADD +++
NOTE! ADD +++ UI - Vikings
NOTE! ADD +++ The speech bubbles “hungry and starving” are shown as long as a Viking is hungry
NOTE! ADD +++ or starving.
NOTE! ADD +++ Notifications in the info screens of Vikings can be removed by clicking the right
NOTE! ADD +++ mouse button.
NOTE! ADD +++
NOTE! ADD +++ UI - buildings
NOTE! ADD +++ Buildings can be chosen with a click on the building site.
NOTE! ADD +++ Full storage slots are highlighted in green.
NOTE! ADD +++ We have added a tutorial button to the info screens of most buildings. You can use
NOTE! ADD +++ the button to review the tutorial at any time.
NOTE! ADD +++
NOTE! ADD +++ UI - misc.
NOTE! ADD +++ The game now highlights what will be selected with the next click.
NOTE! ADD +++ The course of a road during building is now visualized better: If it runs behind an
NOTE! ADD +++ obstacle an outline is shown.
NOTE! ADD +++ We changed the time span after which notifications are automatically removed.
NOTE! ADD +++
NOTE! ADD +++ Misc.
NOTE! ADD +++ Arrows now fly faster.
NOTE! ADD +++ The attack animation of archers has been repaired.
NOTE! ADD +++ Bears now move slower.
NOTE! ADD +++ Performance slumps during autosave have been reduced.
NOTE! ADD +++ Tree stumps rot away over time.
NOTE! ADD +++ A number of buildings is now animated while producing.
NOTE! ADD +++ Many sounds have been adjusted in volume and radius.

NOTE! CHANGED Valhalla Hills, file_size: 733 MB ***TO*** 719 MB

Lumino City updated:

Patch 12.02.2016 (12 February 2016)
Bug fixes.
Optimisations for lower powered systems.

Sid Meier's Alpha Centauri has been updated:

Update gog-14 (12 February 2016)
We've updated the Mac version of Sid Meier's Alpha Centauri.
Fixed an issue with saving. The game should now save & load properly
Fixed an issue where the game's configuration settings (graphics, audio, etc.) would not be saved. They should work as intended now.

I'd like to add that the new build of Train Fever is the last we'll get.

From the developers' page:

From MaGog's logs for 12 February:

NOTE! Probably CHANGED FILE Kona: Day One [In Dev], all_files, Windows installer, English, dl_ver: 20160209-01 (gog-3) ***TO*** 20160211-01 (gog-4) (same for all other languages)

NOTE! Probably ADDED FILE Kona: Day One [In Dev], all_files, Patch 20160211-01 (gog-4) [Windows], dl_ver: ***TO*** 20160209-01 (gog-3) -> 20160211-01 (gog-4)

NOTE! CHANGED Kona: Day One [In Dev], changelog (http://www.an-ovel.com/downloads/chg/chg_1454319762.htm)
NOTE! ADD +++ Patch 20160211-01 (12 February 2016)
NOTE! ADD +++ Notable changes
NOTE! ADD +++ Lighting | Fixed overlit indoor scenes
NOTE! ADD +++ Mouse | Fixed issues with losing cursor
NOTE! ADD +++ Keyboard | Azerty option for keyboard is now supported
NOTE! ADD +++ Graphic | Added "Crappy" graphic settings
NOTE! ADD +++ Graphic | Added "Sharpen" setting for Mr. 4K :)
NOTE! ADD +++
NOTE! ADD +++ Known Major Issues / WIP Features
NOTE! ADD +++ Same as previous.





NOTE! CHANGED FILE Lumino City, downloadables, Windows installer, English (setup_lumino_city_2.0.1.2.exe ***TO*** setup_lumino_city_2.1.0.4.exe; ***TO*** build 12.02.2016 (gog-4); Wed, 03 Dec 2014 14:56:08 GMT ***TO*** Fri, 12 Feb 2016 14:35:17 GMT; 827,808,160 ***TO*** 907,248,928)

NOTE! ADDED FILE Lumino City, downloadables, Patch 12.02.2016 (patch_lumino_city_2.1.0.4.exe; Fri, 12 Feb 2016 14:32:52 GMT; 153,429,616)

NOTE! CHANGED FILE Lumino City, downloadables, Mac OS X installer, English (lumino_city_2.2.0.8.dmg ***TO*** lumino_city_2.0.0.1.dmg; ***TO*** build 12.02.2016 (gog-1); Thu, 04 Dec 2014 14:21:09 GMT ***TO*** Fri, 12 Feb 2016 14:35:36 GMT; 829,642,183 ***TO*** 829,348,617)

NOTE! CHANGED Lumino City, changelog (http://www.an-ovel.com/downloads/chg/chg_1207667103.htm)
NOTE! ADD +++ Patch 12.02.2016 (12 February 2016)
NOTE! ADD +++ Bug fixes.
NOTE! ADD +++ Optimisations for lower powered systems.

NOTE! CHANGED Lumino City, file_size: 789 MB ***TO*** 0.8 GB





NOTE! CHANGED FILE Sid Meier's Alpha Centauri™ Planetary Pack, downloadables, Mac OS X installer, English (sid_meiers_alpha_centauri_2.0.0.10.dmg ***TO*** sid_meiers_alpha_centauri_2.0.0.14.dmg; gog-10 ***TO*** gog-14; Thu, 03 Dec 2015 16:10:13 GMT ***TO*** Fri, 12 Feb 2016 15:42:28 GMT; 619,659,262 ***TO*** 619,662,303)

NOTE! CHANGED Sid Meier's Alpha Centauri™ Planetary Pack, changelog (http://www.an-ovel.com/downloads/chg/chg_1207658936.htm)
NOTE! ADD +++ Update gog-14 (12 February 2016)
NOTE! ADD +++ We've updated the Mac version of Sid Meier's Alpha Centauri.
NOTE! ADD +++ Fixed an issue with saving. The game should now save & load properly
NOTE! ADD +++ Fixed an issue where the game's configuration settings (graphics, audio, etc.) would not be saved. They should work as intended now.





NOTE! CHANGED Baldur's Gate: Enhanced Edition, languages: Audio and text: German, English. Text only: Spanish, French, Polish ***TO*** Audio and text: German, English. Text only: Brazilian-Portuguese, Chinese, Czech, Spanish, French, Italian, Japanese, Korean, Polish, Russian, Turkish, Ukrainian

It seems to me that Broken Sword 3 lost all of its language pack files, but the main exe didn't change. So did the translations get lost?

nope, the language packs were no more necessary. (for those languages)

there are standalone installers for those respectives languages. side effect, you need to download the desired installer (it's quite bigger since it's the full game)