Valve's decision to not police the kinds of video games allowed on Steam short of illegal or "trolling" games came with the announcement that Valve is working on new tools to make sure that this sudden freedom doesn't impede with the customer shopping experience. And this means that some adult games have been put on hold until those tools are ready.
@Love_In_Space, developer of Shining Song Starnova announced that their game has been withheld from the Steam store until Valve implements the said tools that would allow consumers to prevent seeing games, adult or otherwise, that they don't want to see on their feed.
We’ve now been updated by Valve in regards to Shining Song Starnova, the summary is that they are working on new features to give people more control over the content they see and SSS has been identified as needing these features in place before it can go live on Steam. [1/2]— Love in Space (@Love_In_Space) July 12, 2018
Shining Song Starnova is just one game withheld by Valve, though it's unclear as of now what other games have been put on hold. "Yes, some titles are being held," said Valve in a statement to Gamasutra. "We will have more info on this soon."
This is part of a longer running episode with Valve and adult games. Earlier this year, several adult game makers announced that their games would have to change the content in their titles or risk being pulled from Steam by Valve. After a wave of complaints, Valve wrote a blog post announcing that it would not play gatekeeper on its platform and only intervene with titles that featured illegal or "trollish" content.
Valve engineer Erik Johnson also announced new tools that would give customers control over the content they do want to see. However, it appears that these tools are not ready in time for games like Shining Song Starnova to make their debut.
Header image source: @Love_In_Space