The Advanced Features are a set of tools for advanced users, who wish to edit the game's data and get more insight from God is a Cube: Programming Robot Cubes.
Most of those features can change your game experience (such as revealing all solutions for all levels), so use them wisely!
Basically, popular features requested by programmers and people who completed the game at 100% are put in the Advanced Features.

Key features

• an entirely integrated Solutions Browser, to browse all solutions ever found for each level
  
• Levels direct access, to access any level without gameplay restrictions
  
• Campaign levels direct editing, to edit any official level to suit your taste
  
• Game Snippets, to execute specific actions (gif creation with all parameters, statistics, SQL requests, etc)
  
• Online account, to share your progress between several devices and OS (still in development)

Note: the level editor is part of the base game, as it represents a great amount of work to make it available to everyone. The Advanced Features are more for game breaking powerful features and specific actions that only advanced users can perform (such as command line arguments).