I still have a copy from 2006 saved on my computer of this and I'm pretty sure I originally got it from some sort of demo disk or something like that, maybe PC Gamer or Maximum PC - can't remember.
That site talks about Hell of Sand being another new version. That lead me to find this site that still hosts old .jar files of different versions of the game under the Falling Sand title - https://androdome.com/Sand/
This site I found on Reddit titled as "a modern version of the classic Hell of Sand" - https://www.projectsand.io/
I was trying to look into it more and found this blog post from 2006 saying Burning Sand was a version of World of Sand and links to a Japanese site - https://www.kreativrauschen.com/blog/2006/03/29/burning-sand...
That site talks about Hell of Sand being another new version. That lead me to find this site that still hosts old .jar files of different versions of the game under the Falling Sand title - https://androdome.com/Sand/
This site I found on Reddit titled as "a modern version of the classic Hell of Sand" - https://www.projectsand.io/
There was also this game I remember playing back in school that is a lot alike - https://dan-ball.jp/en/javagame/dust/