Almost exclusively free . Since GitHub is for open-source software, the vast majority of games are free to play and even modify.

They met in pull requests. A pull request was less a formal ask than a conversation in a different grammar: "I propose adding a scene in which the city forgets the name of its river," wrote one. "I fixed the ending so the player can choose not to finish," wrote another. People argued politely in the margins of code; they left jokes in commit messages and poems in the issue tracker. Some merged lines of dialogue that had started as private notes and became public consolations.

: A powerful, versatile 2D and 3D engine that is currently one of the most starred repositories on the entire platform.