How to get Vibrant Vendetta:
Go into GFZ1 and beat it in under 10 seconds (without cheating).
Then, in GFZ2, go to the wall directly in front of the waterfall and thok and spindash at it like a madman, you will eventually get inside.
Inside you will find 3 buttons, hit the middle button first, then the right button and last, the left button.
You will be warped to a big green field full of loop-de-loops made out of stairs, run through all of them and you will unlock the "slope" secret. You will now be able to place slopes.
Next, go on top of the 3rd loop from the left, there will be a warper on top, use it.
After you warp, there will be a big slope leading up above the waterfall, walk up this and eggman will be at the top.
Kill eggman.
You will get 99 extra lives, a new triple jump and.. hang on, wrong game--
You will go to a screen that tells you "Congratulations! You have unlocked the real Super Sonic, 5 new mario levels, and Vibrant Vendetta!"
And that's it, have fun! ^_~