Open level editor window Tools > Level Editor
On the left side of the window there is a list of existing levels, select one to see details.
Once selected the level will be spawned on the scene.
On top part of the editor you can see data of this level, in particular list of stages this level consists of.
You can press Change to change any stage to something else.
Also you can press Set this level as current level - after that when you launch the game in the editor exactly this level will be loaded.
Bottom part of the window is for Level Generation. Let’s see how it works, by generation of the new level.
Click + to create a new empty level and select it.
Take a look at the generation section of the editor.
To add new stage increase Stages For Generation number and drag new prefab or follow Create custom stage instruction below (point #18).
You can uncheck toggle near any stage to exclude it from generation.
It contains a list of stages that will be randomly picked to generate level.
Stages count: is a number of stages generated level will have.
Click Generate to generate a new level.
You will instantly see it’s preview on the scene.
You can click multiple times until satisfied with result.
You can also manually change certain stages if you need (point #4 above).
All changes are saved automatically.