Just toying around with some very simple assets and the Scatter plugin by HungryProton. It's an awesome way to randomly place/exclude scenes along curves. The scene runs at a steady 60fps on my system, though OBS seems to be introducing some stuttering when I record.
As an example - there are three different rocks in this scene, instanced through a mutlimesh to make the path
https://github.com/HungryProton/scatter
Tree and rock meshes by Quaternius: https://quaternius.com/
Grass and flower mesh by HungryProton as part of he Scatter plugin
Using Godot 3.2.2