Little test with Pixzels software, the 3D version is generated via the 3 textures, It's possible to edit it manually, but I limited myself to the generated result.
@PortalFallGame Thanks! The penguin is a 2d sprite (aka billboard) in 3d scene (with ortho perspective camera)
The godrays - a mesh (semi cone) with special shader. The same technique was used in the games of 1990-2000s