All Night Nippon Super Mario Bros.

In 8-4, as you approach the end, you'll cross a pit of lava guarded by two Parakoopas before entering a pipe. This pipe leads to a flat area (except for a dip and a pipe). Past said dip and pipe, you'll find the first Bowser, a fake one that is nonetheless difficult to beat because you cannot instantly kill him with the axe like normal - you must either dodge him, or kill him with Fire Flower fireballs. If you cannot (or do not want to), approach the gap just after the pipe while dashing at full speed - do not jump over the gap. You will run into the wall by doing so. Hold Right on the D-Pad for a while until the first fake Bowser is on-screen (you do so because the camera will not scroll otherwise). When he is about one-third of the way across the screen, you can then just hold Down and you'll automatically scroll past him, still stuck in the wall, although the camera is not scrolling. Once past him, you are free to continue on - you are not required to defeat this Bowser.

If you are out of lives but want to continue playing. Press and hold the A button at the Game Over screen and press Start. You will start at the beginning of the world you played last.

Normally, to unlock the four extra worlds (A - D), you need to first beat the game eight times. While that is entirely true, each successive journey through the game gets harder by restricted times and tougher-to-kill enemies. You can avoid both of those and still retain your progress through the game by resetting the console before each playthrough - in doing so, you'll play through the game as you would the first time through, yet still retain your progress to the extra worlds!

To get an extra 1-Up at the flagpole, your Coin and Time counters must be of specific values in relation to each other. Your Coins must be a double-digit number - 00, 11, 22, 33, 44, 55, 66, 77, 88, or 99. At the same time, your Coins and Time must share the same one's digit (the rightmost digit). For example, valid combinations include 11 Coins and 301 seconds, 55 Coins and 245 seconds, and 99 Coins and 009 seconds. Once you touch the flagpole, instead of gaining 100 ~ 5,000 points as normal, "1UP" will be displayed next to it, indicating that an extra life was earned!

Each time you beat World 8-4, the game adds a star to the All Night Nippon Super Mario Bros logo on the title screen.
When you have eight stars, go to the title screen and hold A and press START on the controller