Yay!! Them relating back to Tetris pieces is a cute idea hehe, I didn't even think of that. It reminds me of something I forgot to mention in the artbook, where I considered showing visuals related to the game of Tetris Green plays during that one part (but I got lazy or forgot or something, I don't even have concept art of it).
The pilot IDs were definitely kind of a happy accident, but I think some things make more sense when you look at it that way... I am pleased it turned out that way.
Thank you for reading/enjoying!!