First cross the bridge on the left. On the other side you will find a chest containing crystals and a button: press it. Go back and cross the other bridge. Here, too, you will find a chest containing crystals and a button to press. Thanks to the platforms you have made appear, you can continue. The path is very linear, but you will have to jump very precisely so as not to fall off the small platforms, which you cannot cling to. Along the way you will also meet a couple of Ice Dantini, try to eliminate them quickly. Then enter the door at the bottom.
To overcome the chasm in front of you, you'll need to quickly jump onto the three rafts before they disappear. On the other side, avoid the attacks of the two Dark Dantini by jumping and take them out quickly. On the right are three collapsing platforms, suspended over an icy pool. On them, you will find two crystals and an extra life. Try to grab everything and get out the door at the bottom before the two Dark Dantinis reappear.
Follow the path, jumping on the elastic platforms to overcome the freezing pool and crush the crates you encounter, to get crystals. Go through the short tunnel eliminating the spider at the end and you will find another chest containing crystals. To get over the icy pool you will have to quickly jump onto the moving platforms, which move in the opposite direction to where you need to go. At the bottom, you will find another chest with crystals. Then enter the door on the right.
In this cave, you will have to progressively descend into the huge pit by jumping from platform to platform. There are several spirally arranged crystals to collect. At the bottom you will find the puzzle piece. Grab it to complete the level (and the second island).