Question: I'm looking to publish a game on Steam that contains explicit adult content.

I am seeking to make this a hobby that earns passive income as opposed to pursuing it as a full time job. I would prefer that a prospective employer could not easily track my name back to this game and thus not consider me for the job.

I have read the Steamworks Partner Program here:  

<https://partner.steamgames.com/steamdirect>

And thus understand that for Steam's sake, I will need to identify myself. But can I publish under some sort of pseudonym to prevent a simple Google Search of my name from returning this game? Or will this pretty much be on my so-called "permanent record" for life?

Answer: 
Publish your game through a company that you've created rather than directly.

This probably won't make it *completely impossible* for a dedicated sleuth to associate your person with the organization, but it should make it sufficiently difficult that most people won't even try, especially if you are able to engage the services of a third party (such as a law firm) to act as the registered agent of the company.

The details of forming the corporate entity vary by location (as do the types of entities available) so you may need to consult your local government's documentation on the subject.
Another option would be to release the game through a publisher. Ask one of the established developers in that niche if they would like to partner with you. This will likely be a win-win situation for both of you, because both of your games will benefit from cross-promoting each other. Assuming that your games appeal to the same target audience and have about the same level of quality, of course.

Note that in that case Steam will pay the earnings from your game to the publisher, not to you. So you need to make sure you can trust them to hold up their part of the bargain (whatever it is you negotiated).

Also keep in mind that your publisher might agree to conceal your identity from Valve and from the general public, but they are unlikely to protect you in case of any legal issue.