30% off Brigador: Up-Armored Edition
40% off Brigador: Deluxe DLC Upgrade
40% off Brigador: Up-Armored Deluxe

No longer unannounced, plus I got it wrong and the Deluxe Upgrade is actually 50% off, and not 40% off.

A Fistful of Gun and its Soundtrack just added to the WILD WEST GAMES promo.
https://www.gog.com/promo/20171116_special_sale_wild_west_games

UPDATE
50% off Reservoir Dogs: Bloody Days
50% off Reservoir Dogs: Bloody Days - Soundtrack

The game will be removed soon: https://www.gog.com/forum/general/removal_of_reservoir_dogs_bloody_days_now_50_off

After the Wild West Sale,
Westerado: Double Barreled is still 50% off.

The Weekly Promo started sometime today with no announcement. (I assume it will probably get one tomorrow.)
[link]

By the way, how come they don;t offer for sale Leisure Suit Larry 4?

*snort* *snort*

:)

I guess you knew it. :-)
There is no Leisure Suit Larry 4.

[knocks on stall door] You're not doing coke off my toilet seat again, are you?...

And the sale URL is dated tomorrow as well. More proof of GoG Time Travelling!

Current sales are updated in the Spreadsheet ...

Turok series on sale: https://www.gog.com/promo/20171130_turok

The promo is announced.
But I think many people will not notice the tiny URL:
https://www.gog.com/promo/20171130_platformers_pinball

UPDATE
After I post the URL here, GOG put the promo on homepage with wrong countdown clock.
(countdown clock at promo page is correct.)

Sales Spreadsheet is up to date with the new (very short) promo + new games.

I haven't seen any announcement for Vaporum being 35% off, have you?

Oooooh pretty sure this is Unannounced:

X3: Home of Light Complete

I passed on it during the last sale but I've been eyeing it for a while now. I figure it'll beautifully scratch that space sim itch when I'm looking for something just *a little* less deep and enormous as the "typical" X game. Plus it's my understanding that the expansions added in some of the stuff that was originiall stripped out.