INITIALIZE A VARIABLE TO KEEP TRACK OF WHETHER THE GAME IS OVER. PLACE THE FOLLOWING CODE BEFORE THE MAIN WHILE LOOP:

game_over = False

MAKE THE MAIN WHILE LOOP QUIT WHEN THE GAME IS OVER.  REPLACE 'WHILE TRUE' WITH:

while not game_over:

DETERMINE WHETHER ALL THE ACTIVITIES HAVE BEEN COMPLETED.  PLACE THE FOLLOWING CODE BEFORE SCREEN.BLIT(BACKGROUND,(0,0)):

	# Check if all the activities have been completed
	game_over = True
	for activity in activities:
		if not activity.activity_completed:
			game_over = False