A dedicated streamer set a goal of completing Pokémon Platinum without taking any damage whatsoever. After a lot of time and effort, he managed to do it.
It can take a lot to get good at a particular game, and even more to master it. Some gamers will settle for playing through a game's main story, others will want to 100% it, and if someone loves a game enough, they will want to perfect it. To play all the way through it as if the character you have taken control of is invincible.
How impressive that is ultimately depends on the game being played. Watching someone complete a platformer without taking any damage whatsoever is a sight to behold. Watching someone do it on a Pokémon game is something else entirely. We didn't think it was possible, or if anyone had even thought to try and complete a Pokémon game without taking any damage, but it has been done.
Smallant1 is so familiar with Platinum that one day, instead of just playing through the game again, he would try to do so without any of his Pokémon taking any damage. The rules were fairly simple. Should a Pokémon take damage, Smallant1 would either have to return to the beginning of the game and start again, or to the last conquered gym and resume the game from there.
The beginning of the game actually proved to be one of the hardest parts. Smallant1 went with Piplup to begin with. However, that depended on Turtwig using withdraw six straight times in the game's first battle as well as missing twice. According to the streamer, there is a 0.004% chance of that happening. Instead of fighting those crazy numbers, Smallant1 starts again and picks Turtwig. It takes him an hour to make it past that first battle.
According to Polygon, it took Smallant1 138 in-game hours to complete Pokémon Platinum without taking any damage. The scariest thing about that number is it obviously doesn't include all of the resets. The first actual battle against Starly, for instance, took nine hours alone. Interested parties who did not join Smallant1 on his mammoth journey as it happened can watch the (very) condensed version above.