Classic NES Series: Super Mario Bros.
# A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
How to save and continue
When you die press L + R then select "Save High Score". After that you may turn it off or whatever. When you come back to it at the title screen press A and then start. You will start on the first level of the last world you were on.
Fireworks
Hit the flagpole at the end of a level when the last digit of the timer is 1, 3, or 6.