I backed Mike Shea’s last “campaign” type book, and it was a great setting and collection of adventures. It was designed for levels 1 through 5 (similar to Lost Mines of Phandelver), but then at the back he included an appendix with ideas for, IIRC, a level 5-20 campaign. It wasn’t super detailed, but it was enough to give DMs an idea what to do if their players really liked the setting and wanted to stay down there.

You know how you can read a campaign book and be like, “Why is this so confusing and hard to understand? Don’t they care how hard the campaign is to run?!”

Well, Mike does care – that’s his whole shtick, so I’m definitely going to back this.

It’s called Walker (1987). Directed by Alex Cox (Repo Man) and starring Ed Harris. Not currently streaming anywhere I know of, but if you can find it on DVD or something I highly recommend it. The less you know going in the better. :)

a worldbuilding game such as the quiet year, for the queen or microscope, hacked to set up a concise and thematic noir mystery inspired by fiction like Disco Elysium, The City and the City or The Nice Guys

That sounds amazing. I love the thought of a Nice Guys-inspired campaign setting.

Is the game you’d like to run also Lancer? That would be a wild coincidence.

Edit: Oops, nevermind, I just saw your other comment!

Electric Bastionland has been the RPG I most want to run ever since I bought it years ago.

After watching a surreal Acid Western (which started out deceptively straightforward and veered endearingly off the rails by the final act), I’m itching to run In The Light of the Setting Sun: Bonanza Edition. But I’m at the end of my current FIST: Ultra Edition campaign and don’t want to rush anything. :D