Schedule I, the drug dealing simulator released by TVGS (Tyler's Video Game Studio), has continued its explosion in popularity since its March 24 launch. Recently, it reached 459,075 active players on Steam, enough to make it one of the most successful solo developer projects of all time.

Credit: TVGS
The game, developed by sole developer Tyler, quickly surpassed heavyweights like GTA V, Monster Hunter Wilds, and Marvel Rivals to become the #4 most played game on Steam - surpassed only by Counter Strike 2, Dota 2 and PUBG: Battlegrounds. The game spent over a week holding the #1 spot on "Trending Games," "Hot Releases," and "Popular Releases," and has gradually climbed in player counts until reaching its peak of 459,075 as of yesterday.
Aside from passing industry heavyweights, Schedule I has also cemented itself as one of the largest solo-developed projects of all time, nearly doubling Stardew Valley's peak player count of 236,000, and quickly surpassing famous solo projects like Lethal Company (241,000), Unturned (113,000), Balatro (44,000), and Undertale (11,000).
Minecraft, however, remains the top-selling game of all time, with over 300 million copies sold and approximately 170 million active players as of last year. The game, which originally was a solo project from Markus "Notch" Persson, is estimated to have sold 800,000 copies during its 6-month alpha phase in 2010. As the game was released independently with no Steam data available, it isn't easy to draw a 1:1 comparison. However, it's fair to say that Schedule I has cemented its place as one of the most successful solo projects in gaming history.