From ZDoom Wiki
MENUDEF name is MainMenu and it can be summoned with the menu_main console command. Its content varies slightly from game to game:
- Allows to start a new game.
- Allows to resume a game from a save.
- Allows to save the ongoing game. Accessing it is denied if not currently within a game.
- Allows to access the save and load menus. Heretic and Hexen use this menu instead of the previous two.
- Also called Read this!, merely displays the help screens in sequence.
- Displays a random message asking for confirmation and closes the program.