It bothers me that there is additional functionality in the demo at the start of the chapter. I followed along exactly and when the "game over" screen comes up, the ship is still back there it's just invisible. Pressing space still fires missiles and you can still collide with enemy ships spawning more explosions. I'm pretty sure I didn't miss any of the code. This looks awfully odd and undesirable. :/ Also the enemy ships are in front of the game over screen and I can't figure out how to get them to go behind it.
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