Getting any number of people to play your game apart from a handful of friends and fans is tough, no doubt.
I've been fortunate to be able to be a full-time indie game developer for the last two years and have sold in the thousands-of-copies range of Neofeud. I see many great games moving less than 100 units, and even free games with barely any downloads.
Of course making games that people want to play and promoting those games is important, but a lot of indie game success is definitely luck, even if you really know your marketing, and I am no promotion guru.
But here are some things that have seemed to help:
-Finding a particular niche - in my case, cyberpunk-flavored pnc adventure games - and then finding where those people are hanging out. On forums, social media of various types, Discord, etc. and then trying to spread the word, talk to people.
-Let's players/streamers can have an impact. When my game got featured on Rooster Teeth's Funhaus, that got 250,000+ views, there was a visible spike in the sales graph. But even smaller Youtubers playing your game can tell people, "Hey, someone is taking time to play this, maybe I should look into it too."
-I've done podcasts, Youtube devstreams, etc.. I find that often at least one person will decide to buy my game while people are just dropping into the stream to see how AGS gamedev works, or just hanging out and chatting, giving feedback about their experience having played my game.
-Don't be afraid to ask a fair price for the game, if you do decide to go commercial. Having a price on a game can signal to people, "Hey, this is 14.99, maybe some serious effort went into this." Of course you need to have put a fair amount of work and content in it or people may feel ripped off. But conversely, if you have tens of hours of gameplay and you ask for just a few dollars, people may skip past it without realizing. Ultimately, indie games aren't super expensive compared to AAA games, and the ultimate commodity is really time for many gamers. Just think of how many people you know who have a back log in the game library

(I've got a mountain).
I also highly agree with the point that visual novels, Telltale-style games, hidden-object, and several other genres all basically borrow facets of classic pnc games, and many have been hugely successful.