Success! Here I achieve the (almost) lowest score possible in Super Mario Bros. for the NES. No save states or slowdown was used, but I did increase the frame skip by quite a bit when waiting at the flag poles. Since you probably don't want to watch that, I cut out almost 8 minutes of video where I'm just running out the clock.

I pull off a couple interesting tricks and glitches to make this work. In 4-2, I backwards jump into a few obstacles to scroll the screen without Mario to trick the pipe into taking me to the vine's usual location. In 8-1, I have to perform a pretty precise jump off a goomba to avoid some coins. Also, getting under the first set of 2 coins towards the end of this level takes a very careful jump, and always makes me nervous. In 8-4, I scroll the screen to just the right position to allow me to use some blocks as platforms. No wall jumps are required in this run at all. :)

I show off a bit at the start, but after 8-1 I start to take my time. 8-3 is really a tough level. I took a chance to run and jump past a couple hammer bros. towards the end, but the final 2 I took slow. These are close together, so getting by them the careful way proves to be quite challenging. As you can see, there were a lot of hammers to dodge there.

Source : Youtube