I can be very cute, but I cannot avoid puncturing you if you scare me. You might see me in a in a videogame with rings.

I speak in colors, I cry in shades, I disappear when the sun fades.

I make sirens wail a different tune, A cosmic shift that colors stars maroon. Astronomers love me, so do the docs, Guess my name, think waves, not clocks.

what repeats when first said loudly, but gets softer as it goes on?

I howl and whisper, I roar and sigh, I can be gentle, or wild and high. I can knock on doors, or rustle hair, I'm felt by all, yet I'm invisible there.