You're not really seeing much of anything new shader-wise. Apart from the spiffy new particle system (which still needs a lot of work and optimisation, alas), the main challenge has been coding in all the interdependencies and getting the lighting and colours to look just right in all combinations of: sunny, cloudy, day, night, dawn, dusk, rainy, snowy, stormy etc. There's a simple fog shader to darken stuff lower down than higher up using the heightmap, but it's 90% about tweaking the bloom settings. The other neat trick is overlaying a neat transluscent glow sprite over every light in the…