I really like this guys game it focuses on an OCD nature of gaming. He is a Solo Dev and inspiration to make a solo game on your own. You can read about his career here where he used to work on the Uncharted Series as a tools dev before becoming an indie developer.
I looked at Papers please and it has a really simple game loop of check items on a screen. Reminds me of the arcade games photo hunt. But his recent game Obra Din is aa murder mystery onboard a ship that is done in 3D and all of it is solo development. Both games require a meticulous nature of spotting clues.
One lesson I can take is to make something so different that its a catergory on its own. So you won’t have to do much marketing on it.
He also likes to make his game just work within one level. This is to keep the scope small. This is common from papers please to Obra Din.
Each game has some strong restrictions. Such as limiting the graphics to non-realistic. For Obra Din he made a 3d game but in a one-bit style. papers please just take place at a border pass checkpoint.
He does all the Art, programming, and music. This allow him to have different kinds of challenges during development if he gets tired of one discipline. It may not work for all.
I doubt I can replicate the success of his games but I believe that if you have the right game scope you can make and publish games easily today. Based on interviews Papers please took about 6 months but Obra Din took about 4 years.
One aspect of doing the game by yourself is the satisfaction of learning multiple skills in a project.