This level is only available when the Speedy Comet is in orbit. You will have also need to have completed the Revenge of the Topman Tribe level. These levels are available in the Garden dome in the Dreadnought Galaxy.
This level will be identical to Revenge of the Topman Tribe level and therefore that page will provide you with a good walkthrough on what to look out for. You will have six minutes to complete this level which means that you don’t want to be unnecessarily fighting enemies or collecting Star Bits. If you fail to complete the level within the time limit, you will lose a life.
The only part of this level I would recommend taking your time on is the Pull Star and Cannonball section. You want to make sure you pass through that area without getting hit at all. As you’re more likely to save time by taking your time and not getting hit as oppposed to rushing and getting hit by Cannonballs.
The boss battle will be the exact same, as you need to jump on Topmaniac to make him vulnerable and then spin attack him into the electric rails three times. After defeating him again you will get another Power Star!