The last built-in menu is not built-in anymore in Solarus 1.1!
Now, when the life of the player reaches zero, an event game:on_game_over_started() is called. The game is suspended and you can show whatever you want. You can make a dialog that lets the player chose between "Continue" or "Save and quit". Or you can make a more elaborate game-over menu like in our games, where a fairy saves the player if he has one in a bottle.
And if you don't define the event, game:on_game_over_started(), then the engine just restarts the game.
The Solarus 1.1 roadmap