Kosmic is a speedrunner who usually focuses on Super Mario Bros., but he’s reached the kill screen in Donkey Kong before. With some help, he’s figured out a way to complete that game’s “kill screen,” the point where it’s usually impossible to continue.
At Level 22 of Donkey Kong, there is a bug that causes the game to only give Mario (nèe Jumpman) 400 bonus timer points to complete the level. (The screen displays 4000, but that’s caused by a different glitch.) Playing normally, that’s not enough time to reach higher than the second girder on-screen.
However. If the player has Mario climb the first broken latter, then hold down for four frames then up for one, Mario will climb up off the top of it by one pixel. Continuing to do this, Mario can continue to ascend the screen. When he reaches Pauline’s height, the game will declare the level completed and move on to the next screen.
As it turns out, the bonus count on the Barrels screen is tied to the barrels that Donkey Kong throws, and the timing on those is somewhat random. If DK is slow at emitting those rolling obstacles, rarely, that will give Mario just enough time to reach Pauline at the top, and advance to the next level.
Doing this physically is essentially impossible. The player would have to waggle the joystick extremely quickly (and loudly), yet with the precise timing to consistently raise Mario’s position, to get him up the screen in time, and even if that worked, he’d still have to be lucky enough that Donkey Kong was slow at rolling barrels. But in emulation, with tool assistance, Kosmic managed to get to the top and finish the level. Then using other tricks and glitches, he managed to finish the next three levels (Elevators, Barrels again and Cement Factory) too, before his luck ran out at the next Barrels screen and he was unable to continue.
Here’s his 29 minute video explaining his feat. Or, if you’d like to avoid the general description of what this means, you could start at this point 11 minutes in.
