So there are a pair of things I feel may be worth mentioning here...
First of all: The free-line-of-sight starburst seems to be a viewer-tracking sprite, but when you occlude the disc of the star (...or disable lens flares), the resulting dampening of it reveals there is a smaller starburst "behind" it, for the corona, which does not roll with the camera...
Then: There seems to be another issue with the sprite camera tracking, in additional to the unwanted roll: It would appear sprites are not rotated in such a way that they face the viewer directly, but instead match the world space orientation of the viewer, so if you stand among e.g. a lot of steaming geysers, their respective steam cloud quads are not swivelled like a gawking crowd staring at your smoking car-wreck in the centre, but to all be parallel with the viewplane, giving them a distinct "cardboard cutout" look.
I.e: If I look north, the normals of all sprites will face due south - not only the ones right in front of me, but the ones out to my side and behind me as well. This looks stranger and stranger the larger your field of view is.