Even I have been played Eyewire for more than a year, I have never played starburst cell except for the tutorial. I wonder when the starburst is coming back...
They are not, officially they've finished back when the starburst challenge finished, unofficially we find some here and there occasionally.
you can use cube id 77925 to jump to a starburst cell if you want to see how it looks like, just don't try to play there, please
lol! I will not try to play in that ;;