Three different behaviors that you made:
1. Car drives and parks. Extremely simplistic, I don't care much for vehicles.
2. Boids flock, with the behavior implemented on the GPU. They also avoid terrain.
3. Wind blows and has a grassness map in one channel of the terrain map.

One behavior that is not simple:
Not simple: Any objects in the sea interact with it, creating shoreline foam (the sea is drawn in a separate pass and reads the depth buffer)

Other Behaviors that you made: (backup in case something above doesn't count)
- The road reads the terrain heightmap to place itself, and can dynamically adapt to the terrain.
- The lighthouse lamp spins.