Hey Althasor! It seems that Chrome is the most reliable of the bunch, yeah.. You are completely right, we only tuned the game to increase the cadence the first 5-ish minutes but after that it stays the same.
The game can indeed become more complex very quickly and you guessed an item on our roadmap - considering how calming the experience can be that zen mode is definitely something we are seriously considering.
I left the halo for the cool effect… Right now it signifies that you are restoring the music back and it (thematically not functionally) helps you to bring down more asteroids. But I see where the confusion is for sure and in the future we either going to give it a purpose or maybe get rid of it entirely.
Thanks for such a detailed feedback!