Vampire: The Masquerade - Bloodlines 2 disappeared first. The game was available for pre-order, and according to Epic, it will return to the store soon, presumably after the sale ends. Klei Entertainment's Oxygen Not Included, which was also available for pre-order, vanished as well. It makes sense that publishers wouldn't want their pre-orders in a sale. While there are several other pre-order titles available at a discount, those are Epic Store exclusives.
In a statement shared with Engadget, Epic said, "If a developer or publisher chooses to not participate in our sales, we will honor that decision. Paradox Interactive and Klei Entertainment have chosen to not participate in the Epic Mega Sale and their titles (Vampire: The Masquerade - Bloodlines 2 and Oxygen Not Included, respectively) have been temporarily removed from sale. If players have purchased either during the period when the discount did apply at the time of check out, Epic will honor that price."
Meanwhile, the cost of Hades - Battle Out of Hell seemed to increase, but Supergiant Games reportedly said that was an error. The game is now listed at its original launch price, $19.99, and is on sale for $9.99 during the sale. After that, Supergiant Games will supposedly increase the price to $24.99.
As we noted yesterday, Epic's store has been drawing attention -- some good, some bad -- by aggressively going after Steam's stranglehold on PC games market. While it appears that only two games were pulled, this isn't a great look for Epic.