The indie game market is extremely saturated - there are a ton of great indie games on Steam that will never see the light of day simply because of the sheer amounts of games released daily on the platform.
For reference, over 4000 games were released on Steam in 2016, that’s about 10 games released a day on average.
This is why, unless you have a lot of money, a lot of time and a great development team, you shouldn’t be focusing on making a decent living off indie games. Focus on making a great game, put it on Steam and market it as well as you can. Don’t expect to become a millionaire, because you probably won’t.
“How to make game for steam?” First things first - make the fucking game.
Also, I wouldn’t really take Leinadien’s advice on his “order of importance” list, seeing most successful games on Steam focus first on gameplay, then graphics and then story. Leinadien has it backwards lol
I mean just look at the platinum best sellers for 2016 on Steam - only Fallout 4 and No Man’s Sky have a “focus” on story (and that’s being generous).
For indie games, it’s pretty much (1) gameplay, (2) graphics, and (3) story. Here’s a random top 58 indie games on Steam list that I found on Google. The only indie games there with a focus on story are Undertale and, maybe, the Stanley Parable. Again, to say that these games focus on story first is a bit of a stretch.
If you want to learn how to make good games, the first thing you should do is make some games. I can’t think of a single indie developer that has created a masterpiece game on their first attempt at creating a game ever. You should also play and analyze good/successful games. Take note of elements that make a good game good. Do the same with bad games - what makes a bad game bad? Listen to GDC talks and other developer talks. Lastly, if you get really into it, read some books on game design (although, imo, this last one isn’t really necessary).
99% of people on this forum don’t know how to make a game, let alone a good one. It’s up to you to figure out how to do it. So, don’t just take my word for it - do some research as well.