Fedex14 said:
thank you so much! I got it!
but the comet didn't appear, and I have everything! WTF!
You're very welcome.
Ha ha, yeah that's what happened to me. To make the comet appear you have to have 9999 starbits in the bank! To get lots of starbits quickly I done the challenge on the Melty Monster Galaxy (I think that's it) where you have to use a Rock Mushroom on a track several times. There's a 1-up you can pick up easily on the track, so you can grab it, get loads of star bits, kill yourself and repeat.