I've found 2 secret ways of going ahead the game and it will help a lot if you haven't accomplished corneria.
1. On the world called Meteo asteroid field, when you are about three quarters there, you will notice a circle, go through all of the circles.
ps. Every time you go through a circle, your speed will start to increase so make your timing just right and you will come to katina.
2. The other one is in sector x and this shortcut is after the checkpoint and then you will come across 2 ways, so take the left way and this path is quite hard to get through and you will be able to see some silver flaps and shoot them imediately.
You will notice the silver flaps more and more red until it opens, do the same for all the others until you go across the secret passage like on the meteor world and you get to sector y.
Added by: josh fan , ID#2179