Built as an exercise in animating parametric points and instancing 3d objects.
Starting point: Make Smooth Terrain example file. Modified to animate the Mesh. Added a Make Line Strip Mesh to the parametric grid. Added a single Cube to scene which is then instanced using the Parametric Grid points by Copy 3D Object node.
For more information on animating parametric meshes see this discussion:
For placement of cube geometry one of the methods discussed here was used: