They expire Apr 29, 2026. Or so says the redeem page.

Maybe it's just the sleep-deprivation talking (I got a terrible night's sleep while trying to recover from an all-nighter) but I thought I remembered the included music being somewhat reactive. Maybe it was just well-paced to give that effect. I know I've seen random screensavers which, as a quirk of how their design interacts with human perception, tend to trick the mind into thinking they're reacting to the music that's playing.

I did some quick research and the txt file is apparently just a sequence of timestamps, equivalent to a step file for a one-button DDR game, for overriding the beat detection with predefined timing.

*takes 10 years to research what updates he has missed and downloading them*

From MaGog's logs for 3 May:

NOTE! FAILED to find FORUM for STAR WARS™ Shadows of the Empire™

Ah, you have to try to redeem the codes to see the expiry date. I haven't used the redeem page since a while, the new captchas do not work in my standard browser.

Thanks!

More or less the same, but for different reasons. Google loves to merge stuff into their main google.com domain. Because of that and because I don't like Google Instant, I keep google.com NoScript-blocked by default.

I've given up with NoScript in my GOG profile since they switched to the new web design. I only have installed RequestPolicy. But when these captchas come from a Google server I think I know why they do not appear in my browser. ;)

Tracking with "services" makes things even worse. I assume there's no plugin available which can replace these captchas with a dummy, right? That kinda would defeat its purpose I guess.

EADOR. MASTERS OF THE BROKEN WORLD has been updated:
Patch 1.6.5 (04 May 2016)
Encounter invalid army fix.
Interface stability improvements.
Various stability fixes.

Yes, if they don't send you an email about promo/gift codes that usually states the expiration date, and it's not listed in your account next to them, then checking them out on the redeem page is the way to go.

NoScript works just fine for me on GOG, and like ssokolow, I keep Google blocked, and only allow it temporarily to pass the stupid captcha.
What browser are you on?

From MaGog's logs for 4 May:

NOTE! Probably CHANGED FILE 8-bit Armies, all_files, Windows installer, English, dl_ver: 0.73.606248 (gog-8) ***TO*** 0.73.606493 (gog-9)

NOTE! CHANGED 8-bit Armies, changelog (http://www.an-ovel.com/downloads/chg/chg_1459422114.htm)
NOTE! ADD +++ Patch 0.73.606493 (04th May 2016)
NOTE! ADD +++ NEW FEATURES:
NOTE! ADD +++ Implemented Lag Dialog to show players that are lagging/disconnecting
NOTE! ADD +++ Added error message dialog when host match request fails.
NOTE! ADD +++ Additional AI personalities added to Skirmish and Multiplayer which will not immediately rush the player. Personalities are chosen at random, so some AI opponents will still rush, but it will be delayed by a number of minutes at the start of the match.
NOTE! ADD +++
NOTE! ADD +++ GENERAL IMPROVEMENTS AND FIXES:
NOTE! ADD +++ Improved Harvester logic when deciding where to drop off
NOTE! ADD +++ Fix for co-op campaign stars not always showing up as completed - due to the responsiveness fixes for the game server improvements.
NOTE! ADD +++ Make sure the AI honors game settings that limit structure building (HQ, Nuke Silo)
NOTE! ADD +++ Variety of AI Changes for Single Player Campaign to take into account recent Balance Changes (especially requiring Radar for Rocket Copters and Stronger Artillery)
NOTE! ADD +++ AI will more aggressively respond to attacks on its base (even to its own detrminent, e.g. throwing units away)
NOTE! ADD +++ Mission 19: Leapfrog: Gold Objective: Changed from 15 minutes to 20 minutes to help compensate for the increased rocket turret damage vs. helicopters
NOTE! ADD +++ Adjustments to missions 8, 16, 20, 21, 22, 23, 24, and 25 due to recent balance changes.





NOTE! CHANGED FILE Eador. Masters of the Broken World, downloadables, Windows installer, English+French+German+Italian+Polish+Russian (setup_eador2_2.4.0.22.exe ***TO*** setup_eador2_2.5.0.25.exe; 1.6.1 (gog-22) ***TO*** 1.6.5 (gog-25); Fri, 03 Jul 2015 10:41:13 GMT ***TO*** Wed, 04 May 2016 11:09:20 GMT; 1,042,909,544 ***TO*** 1,170,333,144)

NOTE! REMOVED FILE Eador. Masters of the Broken World, downloadables, Patch 1.6.3 (patch_eador2_2.4.1.24.exe; 1.6.1 (gog-22) -> 1.6.3 (gog-24); Wed, 02 Sep 2015 12:46:01 GMT; 110,234,520)

NOTE! ADDED FILE Eador. Masters of the Broken World, downloadables, Patch 1.6.5 (patch_eador2_2.5.0.25.exe; Wed, 04 May 2016 11:06:06 GMT; 1,954,264)

NOTE! CHANGED Eador. Masters of the Broken World, changelog (http://www.an-ovel.com/downloads/chg/chg_1207659194.htm)
NOTE! ADD +++ Patch 1.6.5 (04 May 2016)
NOTE! ADD +++ Encounter invalid army fix.
NOTE! ADD +++ Interface stability improvements.
NOTE! ADD +++ Various stability fixes.

NOTE! CHANGED Eador. Masters of the Broken World, file_size: 1 GB ***TO*** 1.1 GB





NOTE! Probably CHANGED FILE Moon Hunters, all_files, Windows installer, English, dl_ver: 1.0.2158 (gog-7) ***TO*** 1.0.2232 (gog-8)

NOTE! Probably CHANGED FILE Moon Hunters, all_files, Mac OS X installer, English, dl_ver: 1.0.2158 (gog-7) ***TO*** 1.0.2232 (gog-8)

NOTE! Probably CHANGED FILE Moon Hunters, all_files, Linux installer, English, dl_ver: 1.0.2158 (gog-4) ***TO*** 1.0.2232 (gog-5)

NOTE! CHANGED Moon Hunters, changelog (http://www.an-ovel.com/downloads/chg/chg_1452776767.htm)
NOTE! ADD +++ Patch 1.0.2232 (04th May 2016)
NOTE! ADD +++ Spellblade Boost! The Spellblade’s slash attack now uses a heavier 1-2-3 combo, with the third attack always releasing a tornado.
NOTE! ADD +++ Sun Cultist Boost! The Sun Cultist’s swipe keeps enemies away more effectively.
NOTE! ADD +++ The Sun Cultist’s meteor can be used more easily now, but watch out for friendly fire!
NOTE! ADD +++ (Online) Some visual effects that weren’t playing before are now triggered properly online.
NOTE! ADD +++ (Online) Several optimizations! Online games should run into fewer lag issues.
NOTE! ADD +++ (Online) Adventure award badges are now synched across all players (Rowdy, etc)
NOTE! ADD +++ (Online) Online disconnects should happen a lot less frequently now.
NOTE! ADD +++ (Online) Health bars don’t occasionally stick to dead enemies anymore.
NOTE! ADD +++ (Online) Error messages are more clear when the server could not be reached.
NOTE! ADD +++ (Online) Occasional unbreakable smashables are a lot less frequent now!
NOTE! ADD +++ (Online) Canceling cooking a recipe with the mouse doesn’t get you stuck anymore.
NOTE! ADD +++ (Online) Some hidden opals don’t disappear online anymore.
NOTE! ADD +++ (Online) Updated instructions on how to play online.
NOTE! ADD +++ The “Shieldo” mushroom enemy has new, improved behaviour, including improved ‘shield’ detection and a vulnerable state. Hit ‘em while they’re closed!
NOTE! ADD +++ The Phoenix familiar is now available to those who purchased it, and/or visited our PAX East booth. To keep up on future limited-time offers, join our monthly newsletter[eepurl.com]!
NOTE! ADD +++ The world map runs more smoothly.
NOTE! ADD +++ Visual improvements to several landmark scenes: Tyrant’s End, Bridge of Heaven, Salt Flats, and Raw Embers
NOTE! ADD +++ Fixed an issue with the fox familiar in camp.
NOTE! ADD +++ Fixed an issue where the game would get stuck at the loading screen for some generated world maps.
NOTE! ADD +++ Fixed an issue where fire damage was often being 100% resisted by some enemies and by players (watch out for friendly fire!)
NOTE! ADD +++ AI and animations have been improved for several enemies.

DIVINITY: ORIGINAL SIN - ENHANCED EDITION has been updated:
Update (04 May 2016)
We've uploaded a Czech language hotfix for the Windows version.
This update fixes an issue where the Czech text would not display in the game after selecting the Czech language option from the main menu.

Don't Starve STAR WARS™ Shadows of the Empire™ UnderRail got a flag too. Changelog is from April 14th though.

Firefox. I did not realize the captchas come from Google. They just fail silently for me.

It's sad to see more and more web sites using such tracking services. To see it used here on GOG is even worse.

Do you have google.com and gstatic.com blocked in RequestPolicy? If yes, that's a likely culprit. Just allow them temporarily and try the Redeem Code page again.
If not, what other add-ons do you have installed?