GOG has pulled Hitman from its own store and admitted it shouldn't have released the game in its current form.
In a post on its forum, GOG apologised to its customers, saying: "We've let you down."
Hitman - Game of The Year Edition launched on GOG.com last month and immediately sparked a row about DRM.
GOG is a storefront whose brand is built upon selling games "DRM free" - that is, they can be played offline.
Hitman's GOG page, like that of so many games on the platform, highlighted that it was DRM free. "No activation or online connection required to play," read the prominent message.
However, while Hitman's story and bonus missions could be played offline, its Escalation missions, Elusive Targets and user-created Contracts required an online connection.
This was a warning also displayed prominently on Hitman's GOG store page, although customers said the game launched without it.
You also had to be online to unlock new equipment, starting locations, get mission scores and level up your location mastery.
All this combined caused some GOG users to leave negative reviews complaining about the online nature of certain parts of the experience, with some insisting Hitman didn't belong on GOG in the first place. As of last month, Hitman was on a 1.4/5 overall rating - a terrible user score for a game that was met with critical acclaim upon release.
At the time, GOG responded via a forum post that told disgruntled customers they were free to refund Hitman if they were unhappy, and issued a warning over "review bombing".
That statement didn't go down well, and the thread ended up packed with negative replies that took issue with GOG using the phrase "review bombing" to describe the reception.
Now, GOG has taken action, pulling Hitman from sale and issuing an impassioned apology to its disgruntled community.
"Thank you for your patience and for giving us the time to investigate the release of Hitman GOTY on GOG," a company rep said in the post. "As promised, we're getting back to you with updates.
"We're still in dialogue with IO Interactive about this release. Today we have removed Hitman GOTY from GOG's catalog - we shouldn't have released it in its current form, as you've pointed out.
"We'd like to apologise for the confusion and anger generated by this situation. We've let you down and we'd like to thank you for bringing this topic to us - while it was honest to the bone, it shows how passionate you are towards GOG.
"We appreciate your feedback and will continue our efforts to improve our communication with you."
GOG's line about still talking to Hitman developer IO about Hitman leaves the door open to the game's return - although it's clear now it would have to re-launch in significantly changed form. The question, I suspect, will be whether the GOG release justifies the work that would be required to make the game playable offline in its entirety.