Depends on your definition of success. Personally, I think if the developer is making hundreds of thousands to millions of dollars, that's a yes; but I've met p

Depends on your definition of success. Personally, I think if the developer is making hundreds of thousands to millions of dollars, that's a yes; but I've met people who think if the game isn't a household name, it's not really successful. Anyway, most people have this mental model of the video game industry where there's a measurable, comprehensible number of games, but the actual volume of released games is insane. Anecdotally, one of the most impressive devs I've ever talked with had a full time day job and did solo dev on mobile games on the side. He released 3-4 games within 2 years, 2016-2018 and they all earned around $200k+. But again, you never would have heard of any of these games, just like you don't hear about whatever current hypercasual game has 20 million players (unless you're an addict or monitor App Annie / Steamcharts / whatever else on a daily basis).