Dogmaus: I also think that there is a whole ununnounced game, Scrapland Remastered.
Scrapland Remastered was announced at the start of the sale, in the same post that announced Star Trek Armada 1+2. Easily missed though.
Dogmaus: I think the free DLC for Blasphemous, Wounds of Eventide, has never been announced. It does not have a store page as it comes as an update.
This are rarely announced (though sometimes they are). They're typically considered game updates. This thread is largely about separate catalog entries that appear without announcements.