Super Mario Bros.: Old Times is a ROM hack of Super Mario Bros. with a unique gimmick. The game has been modified to include levels that vertically scroll up or down. However, the screen will not scroll back like with later official Mario games, meaning that in levels where you have to climb up a level, one bad fall can mean Mario's death.
In this run, Asumeh beats the whole romhack as fast as possible, using a few tried and true Super Mario Bros. glitches along the way.
Watch this run being played back on a real console.