I received the Jotun and Sundered email this morning and saw Crypt of the Necrodancer was marked 80% off. I excitedly clicked on it, but when I got to the store page it was still full price.

Is there an error or am I missing a code or something?

The discount only lasted until yesterday at 5PM UTC.

Aaaah... good ol' GOG and its too late emails... (at least you received it before the Jotun giveaway expired :P)

Ah, well that's mildly disappointing, but at least I know. Thank you!