Over 10 million purchases have been made across all platforms.
Stardew Valley

Stardew Valley lead developer ConcernedApe, announced on Twitter that the game has now sold over 10 million copies. The game, initially released a little under 4 years prior, is currently available on most major platforms. It was originally released on the PC but has since come out on macOS, Linux, PS4, XB1, Switch, iOS, Android, and even the PlayStation Vita.

ConcernedApe developed Stardew Valley over four years on his own. The game takes massive inspiration from classics like Harvest Moon and has quickly become a much beloved title. In Stardew Valley, you will get to farm, mine, befriend townsfolk, fish, participate in seasonal events, fall in love, marry, restore a community center, uncover secrets, and try to be the best you possible. It's a really great game that my haphazard description doesn't come close to doing justice.

You should definitely check out Stardew Valley for yourself. You can even bring a friend along because online multiplayer was added a little while back.