Function enabled_modules 

pub fn enabled_modules<G: GameData>() -> Vec<Box<dyn Module<G>>>

The Module of each module whose feature is on, made with its defaults, in the catalog’s order: empty with no feature on. A game installs them once, with Game::with_modules or BasicGame::modules, so turning a module on needs no change to its code. A module that needs arguments is not here: the game installs it, as its README says.