Super Mario 64's Cool, Cool, Mountain level has an infamous 1-Up that's impossible to grab without dying. It's found on the slide but it clips out of reach, so you have to throw yourself into the abyss to catch it, dying in the process. However, one speedrunner has finally found a solution after 27 years.
As reported by GamesRadar, this was discovered by speedrunner PaLiX_ who found that if you wall jump for an hour and a half next to the tunnel, you'll fly outside of the map boundaries. Once here, you can glitch into the slide and instantly grab the 1-Up, proceeding back down to safety.
Safely sliding back down is the important bit - the only solution to get this 1-Up before PaLiX_'s discovery involved dying, making it completely redundant since 1-Ups give you one life, which you immediately lose. But with this admittedly lengthy workaround, you can pick it up and keep it. You just have to stomach a whole lot of "yah!" and "hoo!"s, over an hour's worth.
For comparison, the upcoming Mario movie will run for around an hour and a half, and the original 1993 film was just a bit longer at one hour and 43 minutes, so you could stick on either and fill the time it takes to get this previously impossible-to-survive 1-Up.
Instead of watching the movies, you could do an all 1-Up speedrun, but now you have to tack on an extra hour and a half just for this one, slightly inflating the number. But knowing speedrunners, someone will find a way to shrink that hour-and-a-half wall-jumping magic down. In the meantime, the speedrun subreddit is celebrating this discovery, though some are confused about how PaLiX_ even figured it out, "Your scientists were so preoccupied with whether they could, they didn't stop to think if they should."
Granted, PaLiX_ did clarify in the video that it was done during a 'tool-assisted' run, so it's not entirely clear whether it can be done otherwise, but that hasn't made fans any less excited about solving this near-30-year-long mystery.