In general, creating levels in Unity is a painful experience. You have to type in the values for each piece that you want to add or you have to create everything inside a modeling program and import it, which will require you to have 3D modeling skills.
Other game engines have tools like Binary Space Partitioning (BSP) or Constructive Solid Geometry (CSG), which allow you to build geometry from scratch and apply materials to it to create areas for play. Filling in the gap that Unity has, ProCore3D has created a toolkit that allows for in-editor construction.
We will later on use ProBuilder to polish up our final product; but, in the meantime, we will use Prototype, their free version to build the basic structure and flow of our levels without wasting time, thus making things visually appealing until we polish it. Perform the following steps to install Prototype:
Open the Asset Store once again by going to the toolbar, searching for
Prototype, and looking for the following icon:
After the writing of this book, Prototype will in the near future be replaced by ProBuilder Basic which is still 100% free but has additional features. I've talked with the creators about this, and they've confirmed with me after reading the book that everything discussed here should still work with the new version. For more information on this, check out http://www.protoolsforunity3d.com/probuilder/.
We will now test it out to see whether everything is imported correctly. Create a new scene inside Unity by going to File | New Scene. Once there, press Ctrl + K to create a new cube using Prototype.
With this, we know that it was installed correctly! It may look pretty simple now, but we will be diving even more into using these tools later on.
For more information on Prototype, check out http://www.protoolsforunity3d.com/prototype/.