Software engineer and Line Rider enthusiast David Lu spent 11 years creating this absolutely incredible Line Rider track he titled Omniverse II. It would suck if you spent 11 years on something and the end result was bad, but this isn't that. This is good. I didn't know it was possible for a Line Rider track to have a narrative arc but now after watching the video I'm beginning to question the foundations of my beliefs and reality itself.
And as if spending 11 years working on something like this wasn't insane enough, David Lu wrote an article documenting the history and creation of the track. Even the article about the insane thing that he did is more impressive than anything I've ever done. Not only could I never make what he made, I can't even understand his explanations of how he made what he made.
Keep going for the full Line Rider track, along with a video essay discussing it in more detail. It goes way beyond some guy just sitting in his bedroom all day playing around with a game.
And a video essay going into the background of Omniverse II.