Wie kann man solche Simulationen selbst erstellen?

With a computer program that “knows” physical laws and applies them to a scene.

These are https://de.wikipedia.org/wiki/Physics engine (while these are only points with radius, they can be calculated without much buckling)

These are, for example:

• https://box2d.org/
• https://github.com/bulletphysics/bullet3
• https://github.com/jrouwe/JoltPhysics

Otherwise, something like this can be without much code with game engines like Godot or Unity to be assembled. There are also independent applications, such as algododoo or KDEs Step (on Linux) for these games.

This also goes on the web, but is not necessarily user-friendly: https://physion.net I found here an example where someone built such a course with country flags: https://app.physion.net/scenes/first-marble-race-0001