Paper Sorcerer has been updated to version 2.5 ! You can see the changelog here :)

would this help?
https://api.gog.com/product/1432208050?expand=downloads,changelog,expanded_dlcs
it is accessible for everybody. It doesn't tell you the actual installer filenames (and the game version), but you can still track what installer/patches are available, their size and the gog version.
and the changelog

I've created a changelog thread for Paper Sorcerer:

http://www.gog.com/forum/paper_sorcerer/changelog

Thanks for this ! (and I've updated the link I was giving in my message).

Windward was updated (GOG-4).

Patch 2015.07.19 (21.07.2015)
- Stationary turning is now based on the “minSpeed” value as well.
- Challenge level now sets the default “minSpeed”. 200% challenge means minSpeed of 0 (0% speed when sailing into the wind).
- Adjusted wind effectiveness curves for all ships. They should now sail at maximum speed from a much wider range of angles, depending on their sail configuration.

Here are the rest of the changes they seemed to skip over.

- Pirate raid quest is no longer obtained from towns. Instead it will show up automatically when pirates raid the region the player is in. It will now also complete properly when all pirates are defeated.
- Several controller-related tweaks to improve controller support.
- Changes related to preparing Windward for Android TVs (NVidia Shield devices).
- Added /set playersForRaids = # replacing /set moreRaids = true. The # represents how many players are needed for pirate raids to occur in non-frontier regions. It’s 5 by default.
- /delete <regionID> has been renamed to /deleteRegion <regionID>.
- /remove can now be used to remove options set by /set.
- Added a new ship with a unique ability. It’s unlockable the same way as the Turtle Ship. Find a Pirate King sailing one, defeat it... profit!
- Fixed low graphics quality water in regions with size above 256.
- You can now set sailing speed in-game using /set minSpeed = # and /set maxSpeed = #, where # is a value between 0 and 1. By default minSpeed is 0.65 and maxSpeed is 1.0. If you set minSpeed to 0, it won’t be possible to sail directly into the wind anymore, forcing players to use tacking ([url=https://en.wikipedia.org/wiki/Tacking_(sailing]https://en.wikipedia.org/wiki/Tacking_(sailing[/url])). Note that minSpeed set to 0 is effectively “hard mode”. You won’t even be able to turn your ship if your sails can’t catch the wind. Note that AI is currently not smart enough to use tacking, so you may find them stubbornly sailing into the wind. Slowly.
- Fixed an issue with the server-side config settings not taking hold when switching worlds.
- Floating loot should no longer disappear quickly when going outside the 256 boundary on larger maps.
- Wind now affects turning speed while stationary.
- Wind will now vary from 50% to 100% strength (before it was from 35%).
- Added in-game /help command that links to https://docs.google.com/document/d/13ubvckpWIGerOuhTVWxguSmY8pIboPtAmf06daHZAZ8/edit?usp=sharing
- Sail health now affects stationary turning speed, reducing it down to 25-75% with sails gone, depending on the challenge setting.
- Reduced contribution requirements for new ships from 5000 to 3500.
- Increased zoom while in town to let you see your ship easier while customizing it.

Source - https://drive.google.com/open?id=134aQGWrGfiwQFpcmsk0IxLsfS8WcB9rrXez2XNJVnB8

From MaGog's logs for 22 July:

NOTE! CHANGED Paper Sorcerer, changelog (http://www.an-ovel.com/downloads/chg/chg_1207664363.htm)
NOTE! ADD +++ Patch 2.5 (22.07.2015)
NOTE! ADD +++ Added Arms and Armory section to menu, displays all weapons and equipment in possession, as compared to Equip menu that only shows what each character can equip
NOTE! ADD +++ Edited switches to get out of hidden doors/doors that use keys on 9-2 and elsewhere to make them easier to notice and understand what they do at first glance
NOTE! ADD +++ Edited training descriptions to remove typos, including Defense training description
NOTE! ADD +++ Blind II feedback fixed for levels 2-5
NOTE! ADD +++ King Demon fight not always triggering fixed
NOTE! ADD +++ Skeleton's absolute defense fixed
NOTE! ADD +++ Basic and Master Tower Runes fixed, stats now match description
NOTE! ADD +++ Added minor event to 1-1, hint for later puzzles

NOTE! CHANGED FILE Paper Sorcerer, downloadables, Windows installer, English (setup_paper_sorcerer_2.2.0.5.exe ***TO*** setup_paper_sorcerer_2.3.0.6.exe; ***TO*** 2.5 (gog-6); Mon, 15 Sep 2014 16:03:30 GMT ***TO*** Wed, 22 Jul 2015 09:08:23 GMT; 150,347,744 ***TO*** 151,012,728)

NOTE! CHANGED FILE Paper Sorcerer, downloadables, Mac OS X installer, English (paper_sorcerer_2.0.0.1.dmg ***TO*** paper_sorcerer_2.0.0.4.dmg; ***TO*** 2.5 (gog-4); Mon, 15 Sep 2014 13:45:50 GMT ***TO*** Wed, 22 Jul 2015 09:08:34 GMT; 168,617,120 ***TO*** 167,777,135)

NOTE! CHANGED Paper Sorcerer, file_size: 143 MB ***TO*** 144 MB





NOTE! CHANGED Screencheat, image: http://images.gog.com/e09805d0ec16393666ca79df39609c1c2e1695e032f17c563ac17c18eac6c6b7_100.jpg ***TO*** http://images.gog.com/872ca41277ee3bf2057e573f28041d8800297dd40fea0e869f9ac82285d6dd0b_100.jpg





NOTE! CHANGED Windward, file_size: 50 MB ***TO*** 51 MB

[I don't own this game, so MaGog will not be able to report about file changes]

Wow! This is awesome! Thank you!

How did you find this? Is the GOG API documented? Do you know of any other options beyond "expand=downloads,changelog,expanded_dlcs"?

From MaGog's logs for 22 July:

NOTE! CHANGED Metro: Last Light Redux, forum: http://www.gog.com/forum/metro_last_light_redux ***TO*** http://www.gog.com/forum/metro_series

Thank you very much for taking the time to respond, it's greatly appreciated.
I guess +1's don't do it for you, so I have only gratitude to offer. :-D

This likely has to do with the fact that they forgot to compress the images in an earlier patch and they have fixed this in the newest patch. This made the game jump from a little over 150 MB installed to well over 800 MB installed. Then this is again compressed for the standalone installer.

So the images being compressed now probably helped bring down the standalone installer compression a few MB.

From MaGog's logs for 23 July:

NOTE! ADDED FILE Outcast 1.1, downloadables, Patch 1.1.6.19100 (patch_outcast_2.3.1.23.exe; Patch 1.1.6.19100 (gog-23); Thu, 23 Jul 2015 14:44:45 GMT; 3,608,128)

NOTE! CHANGED Outcast 1.1, changelog (http://www.an-ovel.com/downloads/chg/chg_1207658853.htm)
NOTE! ADD +++ Patch 1.1.6.19100 (23.07.2015)
NOTE! ADD +++ This update fixes a potential crash when exiting the game as well as other crashes.

Ah-ha! So that must be the mysterious update!
I see the notification number, but once I get to the library the site does not tell me what it is. Thank you, mrkgnao! :)

I've got notifications for Outcast, Legend of Grimrock and Broken Age, but none of these offers me a Changelog if I check them out. Is this a bug or didn't they get any Changelog entries? What's the use of having this Changelog, if it doesn't work and I have to search through this thread regardless?