Kayato: First of all: thank you for your great work here!
I was comparing my order history with your list and i noticed some things
-I seem to have not seen SOMA as giveaway on 28/12/18
About Permanently Free Games I can say
-AKALABETH : WORLD OF DOOM is in mine account since 24/12/2014
-Dragonsphere was free until 31/12/2015. I redeemed it on 03/03/13. I have no idea how long it was free
Are you also taking into account the movies given away?
27/08/14
TPB AFK: The Pirate Bay Away from Keybord and The Art of Playing
22/11/14
The Gamers: Director's Cut
Last thing, I have Spelunky added on mine acount on 18/06/16 but I've no idea where it come from!
Startrail: Hiya! :) A quick google search will turn out references for the SOMA give away
https://www.dsogaming.com/news/gog-is-giving-away-for-free-soma-for-a-limited-time/
Thanks for the new start dates for Akalabeth :) I'll update that.
I actually took Dragonsphere out when it became not free, since it's technically not permanently free anymore. But maybe for accuracy, I should leave it there and update the description accordingly.
Nope movies are not covered. There were too brief, so I decided to eschew them.
Spelunky was given if 5000xp (approximately 5 USD) was spent during 2016 summer sale :) See this
post About SOMA I was meaning I can not find it in the List of Temporary Free Games - Giveaways Part 1 and 2 (sorry I'm using google translator)
About Dragonsphere I saw Warsow still on the list so i thought that Dragonshper should be too.
Thank again for the great work.