I ordered a sample of Nemosine's new Blue Snowball Nebula Twinkle from Goulet to try out. My first impression was that there is a scary amount of glitter in even the small sample vial. I wouldn't put it into a pen I was scared to dismantle for cleaning. Unfortunately, the picture doesn't show it well.
Sticking with the brand, I loaded it up in a Nemosine Singularity with an 0.8mm stub and made it a part of my daily carry kit for several days. The ink is sparkly. Even on cheap paper, if you look at it right, it shows up. Carrying my pen nib up resulted in a visible ring of glitter around the piston. I recommend agitating the ink before you write (with due care, of course).
Surprisingly, the feed didn't seem to suffer at all. I disassembled the pen after a good flush and didn't notice any particulates, and there was no hard start or skipping with this ink.
This ink has minimal water resistance, and seems to do best on paper that doesn't quickly absorb it (for the sparkly effect, you want the sparkles to stay on top of the paper). On normal paper, it dries well. It's not the smoothest ink, which I attribute to the glitter.