Creating a .c2g file using built-in editor?

[H2O]

Since Version 2.0 of Chip's Challenge 2 this is possible

No extra program/editor is necessary any longer to create a basic set, everything can be done from within the game:

• Open CC2
  
  
• Menu: File -> Editor
  
  
• Open your level and make sure to record a solution, if you have already done so, press F3 to watch the full solution, and save the level.
  
  
• Menu: Level Set -> New
  
  
• Create a set by giving it a name an add your level to it, if you want to share it in the workshop, you need to add a preview image for the set in the dialog as well.
  
  
• Share your level set