
I hadn't heard of Russian Fishing 4 until PCG's Wes Fenlon noticed it was weirdly popular on Steam. The game's been available since 2018, launching on Steam in November 2021, and since then it's steadily built a considerable audience over time: per SteamDB's three year charts, it was pulling in around 7,000 concurrent players after launch, and three years later averages just over 20,000 concurrent players every day.
There are currently 21,500 people playing Russian Fishing 4, and nine days ago it hit its all-time peak of 25,352 players. Bear in mind it's also available directly from the developer, so Steam's only a portion of the playerbase, and we're talking about one very popular fishing game.