or you could build all your games acting like 1 big game ....e.g ( create a project, make your games inside(layout /events for game 1,layout /events for game 2 ,layout /events for game 3 )then the main game contains all of them)
and when u want to play a game inside ur app, press the button for it, cant think on a better way, unless this is not what u meant. how u do the games inside that depends on you, there is no " how do i " but more off "how i will?"