From the System Rules:
To play Sea of Skies, you're going to need a lot of Icehouse pieces of all sizes, though colors don't matter in the least. You may have plastic ones or fancy crystal ones. They may be hollow or not. Doesn't matter. What does matter is that they are all the same style (made of the same material, hollow or solid, etc). All of them need to be folded paper or hollow plastic or solid gold. You'll need a bunch, so if you don't happen to have a bunch lying around nor the money to buy a bunch of plastic ones, I recommend you print up a bunch of the pyramid patterns on cardstock and assemble them.
Challenges in Sea of Skies are resolved by leaning pyramids against your Attribute pyramid. When leaning a pyramid, it must be touching the table AND the Attribute pyramid. Further, they may not lay flat on anything. These may touch other leaned pyramids as well, so long as there are no side is flat against anything else (the table, the attribute, another pyramid, your hand, etc) and it is touching both table and Attribute. You may use both hands to place a pyramid, but the only thing the second hand may touch is the point on the appropriate Attribute.