Tend Liar's Bar's bar and check every patron's Papers, Please documents. Liars get the revolver the hard way.
You're the bartender at Liar's Bar. Before anyone sits down to play, they have to show you their papers.
Foxy, Bristle, Toar, Scubby, Cupcake, Gerk, Kudo and Tusk come down the stairs one by one. Each one slides real Papers, Please documents across the counter: passports from all seven nations, entry permits and Arstotzkan ID cards. Their passport photo is a mugshot of them.
Papers, Please's rulebook adds new rules as the night goes on: no Kolechians, foreigners need an entry permit, citizens need an ID card. Every wrong call earns a Papers, Please citation, and three citations end your night.
Solo. Everything you see is read from your own copies of both games: the bar, the characters, their animations and blood effects, the revolver and gunshot come from Liar's Bar, and the documents, rule wording, cities and stamps come from Papers, Please. You need both games installed.