I'm not actually crazy about the Sun mechanic, since it seems to more heavily incentivize defensive play (quickly popping single chains adjacent to sun puyo, or in order to offset to trigger a sun puyo) as opposed to long chains. However, that still feels like more decisions to make than Fever (a mode which I once took umbrage with, but have since made my peace with), and it also never takes you to an entirely different board like Fever, so I can't fault it too much; it just requires a shift in thinking compared to PP2, more than you might assume at first.