Grab the font for the Game Over screen here:
Create an Assets folder in FileSystem
Add the font to it
Create a New Scene with Control Node as root
Rename the Node to GameOverMenu
To Center everything add a CenterContainer Node
To layer options vertically add a VBoxContainer Node
In the Layout property of VBoxContainer
Set Custom Minimum Size X to 512.0px
Set up the font as the theme for this scene
Select the GameOverMenu Node
In the Theme property add a New Theme
Quick Load the Default Font
Set the Default Font Size to 64
Add a Label as a child of VBoxContainer
Set Horizontal Alignment to Center
As children of the VBoxContainer
Rename them to RestartButton
Set the Text property to TRY AGAIN
Set the Text property to QUIT
Add a New Script to the GameOverMenu
Create a function called game_over
Pause all nodes in the scene tree
Make the GameOverMenu visible
Make the Mouse Cursor visible again
Connect the pressed signal
Unpause all nodes on the scene tree
Connect the pressed signal
When the game_over function runs
The entire game is paused
We want the GameOverMenu scene
To be the only one which is NOT paused
Select the GameOverMenu node
Return to the Player scene
Add an instance of the GameOverMenu scene
Add a reference variable for the game over menu
Instead of quitting when hitpoints fall below 0
Call the game_over function in the menu