Basically, they are the comets that you encounter in chapter 8 Eta Astropelecae: Artifact Recovery Mission, taking place in Eta Astropelecae respectively, in waves 74 and 79 you encounter these Ice Comets, the bigger ones multiply to smaller ones similar to supernova debris and unlike supernova debris, all of the coins they drop are in the exact same size, being the big ones, they can also slam into the ground sometimes.
It would be really cool if they reappear in CIU, the screen probably should be at the normal zoom and unlike supernova debris, they could come from multiple directions other then left or right, it would be a banger really.
It would be cool to see on ice planets, name the mission type ice storm and the boss would be the ice cubed, but it would be tricky to do in space tho, and there is no planetary missions yet
I mean to be fair, it would be illogical to have lightning strikes in space, but in CIU that is apparent, and since the ice comets are also on the same planet, they could be possible too.
That is already in the game, have you tried going into the lightning strike-type planets? Those do exist, and if you haven’t, you can clearly just go to the shop and see one of the shields you can buy that let you access them in the first place.