I think I got everyone here. If you've been quoted here, you've entered for one or more games whose keys turned out to be invalid. Feel free to change your entries. If by next week there are still entries that are invalid, I'll just enter you for whatever you wanted that was valid.
Cavalary: As far as I know
Gothic 3
Breach and Clear
Desktop Dungeons Enhanced Edition
Dust: An Elysian Tail
The 7th Guest
Wizardry 6+7
weren't given for free, so those should still be valid at least. Or were they for spending X amount at any point? Checking cached version of the now no longer available mix, doesn't seem like it. (There's
an archived version of that mix too, just missing Warhammer® 40,000: Rites of War ("Free with a pre-order of Gladius - Relics of War from the 10th to 26th of July 2018") compared to cached page.)
I'm in just for Gothic 3.
That might be the case. I know at least some of them were codes from "spend this much" etc. The earliest ones are something like 4 years old so I don't remember how a lot of them ended up in my account.