Doing it in 6 minutes is easy, since you've only got to do the first eight zones. Bosses - Spindash, they'll come over you and die fast. GFZ1 - Thok like mad, when you get to the bridge, it should be about 5/6 seconds, thok ONTO the bridge, the steps slow you down. If you fall into the water, try again. The rest - Don't go slow, but no extra effort is really needed... try the general shortcuts though.