Players can customize their own worlds on the platform. Many illegally upload songs — called “bypassing audio” — and some make intense tracks in a new genre, robloxcore.

Fast forward to 2019 and Tommy discovered how similar the Roblox "oof" sound effect was to the sound he made for the game he worked on, so he decided to contact Roblox.

Roblox Studio is, like the game, free. Developers can make money through Roblox with its Developer Exchange program, or DevEx, which gives developers 25 percent of a game’s earnings.