Ive done one myself. Very fun and very valuable project, with alot of optional deapth.

Solar system simulation is another fun one, leaning more into nummerical differental equations solving.

Though in this case there's not much more than 500 points, which even if you scale up is manageable.

It’s less about the number of points and scaling and more about understanding the fundamentals. Any sort of particule simulation (which is the easiest way to get into cloth, soft body and fluid dynamics) requires about the first half of that paper I linked anyway.