I'm not sure i have a good solution to suggest, but I feel like this is worth mentioning. I've noticed this when playing the Challenges+ and using the multiplayer power ups, etc. The issue is that any words on the screen (to announce the power up is going to happen, for example) get in the way of seeing the orbs. The biggest issue is with the invaders on Spin mode. It's REALLY hard to see through them.
I imagine you don't want to raise them up too high, so they can be read. But maybe they do need to appear a bit higher and maybe the font could still be easy to read but not as thick? Or one could change the opacity of these items?