Geometry dash is special, I remember playing it in its first years back in 2013-2015. It was cool then but never super popular, but man have they worked on it and made one of the coolest and most powerful level editors ever. Haven't played it myself since back then but my younger half-brother and all his friends are crazy about it, and I keep up to date with the unbelievable levels people make. And the frame perfect world records.