This is the only Power Star in the Bubble Breeze Galaxy. To unlock this galaxy you find it in the Kitchen dome and will need 19 Power Stars.
Avoiding the Poison
When you arrive in the galaxy you will see that a majority of this level is a number of small land platforms that are surrounded with poison. Mario will instantly drown if you fall in the poison.
You will need to need head to the right and follow the small island of platforms. This will take you to a machine that produces giant bubbles. The bubbles are going to be your way of travelling through this level without touching the poison.
Riding the Bubble
When you jump in the bubble, your camera view will be shifted to a aerial view. You can control the direction the bubble by using your cursor to blow air, which will push you in whatever direction you desire. To blow air you can either press and hold A and in handheld you can do it by tapping.
Once you’re in the bubble head back past the island you started on and head upwards. As you head up you will see the first of the Star Chips out of five you need to collect. You will also be blown by giant fans that push you towards the right direction. Along this path you will find the other Star Chips as you navigate the poisonous swamp.
On this path you will also encounter Floating Mines, which if you touch them will burst your bubble and cause you to fall into the poison, killing you. After avoiding the mines and collecting all five Star Chips, a Launch Star will appear.
Taking the Launch Star transports you to another small island, where you will again need to ride a bubble. As you navigate your way through a path filled with Coins and Floating Mines you see a wooden obstruction. This is easy to get past by simply entering the gap and have it take you to the other side. Touching the wood wont burst your bubble. You will then be met with rotating wooden doors. Take care when passing these as they can sometimes push you into the mines.
Once you are past this section you will see a island below you with a button with an exclamation mark. You need to exit the bubble, which you can easily do by spinning or jumping. To press the button you need to ground pound which you can do by jumping and pressing ZL. When the button is pressed it will open the wooden door infront of you for a limited time. You have to get back into a bubble and blow through.
After getting through, all wooden doors from that point onwards will open when your bubble touches them. There will be a greater concentration of mines as you make your way closer to the Power Star. The Power Star will at the end and floating in the middle of an island being orbited by two floating mines. All you need to do is touch the Power Star it will be yours and the level complete.