I spent some time playing all their games

And let's say that the 6km run was made before BScotch updated the game to make it more difficult
Yet I'm faaaaaaaar from some other guys. I stopped at 6000 because I was bored in fact. Could have continued as long as I wanted. (Same goes for those who just beat my record to be the first on the leaderboards ^^ )
Since you're at 2020 you could continue a long time, but it'll be difficult.