This Seeking Tech guide will explain how you can get to the floating island in the Sky Garden level of Astro Bot.
Use the following video as a reference:
For the first step, you need to head over to the pool area.
Next, you need to grab the octopus power up.
Afterwards, back track and then use your power up to go on top of the giant rubber duck.
You can then inflate to get to the floating island.
You can go even higher on the island to find more hidden coins on the tree.