I can see they went the same path as me for the water 
Normal bump map for waves and SDF for shallow water around the shore.
It seems they maybe have js implementation of Unreal Engine Sky Atmosphere Rendering Technique for skybox.
I can see they went the same path as me for the water Normal bump map for waves and SDF for shallow water around the shore.
It seems they maybe have js implementation of Unreal Engine Sky Atmosphere Rendering Technique for skybox.