Epic has once again took a page from Steam's book and announced a "mega sale" that includes both percentage discounts and an additional $10 off every game priced $14.99 or higher on the Epic Games Store. It seemed to be smooth sailing for the sale, but then two major games suddenly vanished from the store.

Vampire: The Masquerade - Bloodlines 2, the upcoming action RPG, disappeared first, and nobody was quite sure what to make of it. It was briefly available for a discounted price, but then suddenly, it was gone. Trying to access the game's store page currently returns a 404 error. An Epic representative told Kotaku that Vampire: The Masquerade publisher Paradox chose at the last second---or after the last second, technically---to not participate in the sale.

"If a developer or publisher chooses to not participate in our sales, we will honor that decision," the Epic rep said in an email. "Paradox Interactive has chosen to not participate in the Epic Mega Sale and the game has been temporarily removed from sale. If you've purchased Vampire: The Masquerade - Bloodlines 2 during the period when the discount did apply at the time of check out, Epic will honor that price."

Shortly after Vampire exploded into a figurative cloud of bats, Epic director of publishing strategy Sergey Galyonkin made a similar comment on Russian site DTF, which the Epic representative confirmed was accurate. A little later, Galyonkin made another comment on the same site, saying that he initially thought Paradox was aware of how the sale would affect its games, but "after a little investigation, it turned out that I was wrong."

Paradox would not go into specifics about why the removal happened when it did, but a representative pointed me to a thread that included Galyonkin's comments. The publisher also provided Kotaku with a statement.

"We are in discussion with Epic regarding the temporary removal of Vampire: the Masquerade - Bloodlines 2 from the Epic Game Store," read the statement. "The game will return to the store soon! Any purchases made while the game was discounted during the Epic Mega Sale will be honored and no Masquerade violations will be assessed."

The other game that was pulled was space station survival sim Oxygen Not Included, the Epic Games Store page for which also gives visitors a 404 error right now. Developer and publisher Klei Entertainment has yet to comment on why this happened. Kotaku reached out to Klei for more information, but it has not yet responded.

"If a developer or publisher chooses to not participate in our sales, we will honor that decision. Paradox Interactive has chosen to not participate in the Epic Mega Sale and the game has been temporarily removed from sale."

It's worth noting that neither of these games are Epic Store exclusives, which could put them in an awkward spot on other stores. The structure of this sale, after all, is unusual; the additional $10 off games priced $14.99 and higher comes "courtesy of Epic," meaning that Epic itself is taking the monetary hit, so companies like Paradox and Klei can't easily match those prices on Steam. In Paradox's case, it's doubly dicey, seeing as Vampire: The Masquerade - Bloodlines 2 isn't out yet. Why pre-order it anywhere else if Epic could, theoretically, discount it again before it's released? Some people have pointed to regional pricing differences that would've led to impractically large discounts on an unreleased game in some territories, as well.

Epic's bouncing baby store has had other first-time mega-sale-related hiccups, as well. Hades, the early access roguelite from the makers of Bastion and Pyre, was briefly priced incorrectly at $6.99, and developer Supergiant corrected it with a confusing increase. "We apologize for any confusion this caused and hope customers who got the deal enjoy the game," Supergiant said on Twitter.

Supergiant has brought Hades' base price back down to $19.99, where it will stay for the duration of the sale. However, it's no longer offering a 25 percent discount on top of Epic's discount, meaning that Hades is currently priced at $9.99. "After the sale is over, on June 14, we will be raising the game's retail price to $24.99," the developer said in a statement. "We had intended to raise the retail price of the game soon, but made the decision rashly as part of the sale---we didn't provide advance notice to our customers, despite previously stating we would do so. That was our mistake, and we sincerely apologize. To all our players, thank you for your patience and understanding around this."

It is, to an extent, understandable that the Epic Games Store wouldn't nail running a store-wide sale on its first try. After all, it took Valve ages to get Steam sales right, and even then, Steam still regularly goes down at the outset of big seasonal dealstravaganzas. But this comes on top of Epic's barebones feature set, other assorted errors, and unpopular penchant for snapping up exclusives. Watching a company with all the money in the world stumble through the process of launching a store doesn't inspire much faith in that store's future prospects, even if the roadmap ahead looks significantly more acceptable than the pothole-ridden road we're on right now.