(:usage "Usage: ~A <source> [options]
Options:
  -o <filename>         - Output filename
  --js <filenames...>   - List of extra .js files to include in the game
  --css <filenames...>  - List of .css files to include in the game. Default is in extras/default.css
  --body <filename>     - Alternative page body. Default is in extras/body.html

  -c                    - Just compile the game to a .js file without making it a full web page
  --beautify            - Make the JS content pretty. By default it gets minified.

Note that the files in extras/ are not actually used. They're just there for the reference~%")