The Spiral chapter in Maquette is a very different level to the ones that come before it, all dark tones and scary floating landscapes.
The path is pretty linear for much of the level, especially in the earlier portions. Make your way along the path in the cave until you come to the outdoor section. Follow the only available path until you find a lever.
Pulling the lever will cause a new pathway to form, and you can follow this to yet another lever. Pulling this will cause a pathway to form directly ahead of you that is broken in the middle, and another one to form to the right. Follow it to a small building that contains a miniature version of the level.
There is a small piece of path that you can place in the broken section to give you access to yet another small building that is close to the central part of the world. And if you jump up on the rocks beside the tiny model there is a small switch that you can hit to form a bridge to get to the main structure.
Walk all the way up to the main structure and follow the corridors until you reach a room with a marble face on one end and a hole in the wall on the right. In the room on the right, you will find a similar marble face lying on the ground, and some small pillars nearby. Arrange the pillars to form a ladder of sorts, then climb up the large face in the other room.
When you reach the top, continue through the level along the only available path until you reach two rooms, one with a large key and one with two smaller keys. You need to make a medium-sized key to progress.
There is little inherent logic here unless you manage to spot that the small holes the two smaller keys are in look like the room you just left that had the very large key. This is hard to spot because of how dark it is. Pick up the small key on the left and place it in the hole on the right. Then, walk back into the dark room and pick up what will now be a medium-sized key.
Drop the key into the hole on the right so that is forms a sort of bridge between the wall and the floor, leading to the left side of the hole. Go back into the dark room and walk up the large key to a secret gap above the room, where you will find another key. Use this key to open the wooden door in front of you in the brightly lit room.
You will come to two small models towns, side by side. On the wall to the left and right are two additional pieces. Grab the piece on the left and put it in the model on the left, as shown above. Do the same with the other piece on the right, place it in the right slot as shown above.
This will cause two large versions to spawn in, and you can walk across the top of them to cross the next room. As strange as this will sound, you want the tower building on the right to sit slightly crooked. The large version will be exactly copying the positioning, and if not a little crooked it will be incredibly hard to make the small jump you need to make to get through the section.
You will come to crystal on the other side, and the end of the level.