That doesn't make it a "level editor for [a] game engine", but it certainly should give you more than enough tools to build a networked tic-tac-toe game.

that's why... GUI objects that have intrinsic knowledge of networking are actually really powerful and useful.

It looks like Shoes is intended to be the graphics engine for writing Ruby apps including HH, and HH is supposed to be the easy-to-use general purpose programming language.

I would be curious to see how non-trivial applications fit within the Shoes framework. My experience with ambitious frameworks has been that they work great until you want to do something that isn't perfectly aligned with its intent/charter/design, then you start fighting them really fast. Maybe Ruby or Shoes offer ways around this, but if you have to write non-trivial network or disk i/o code maybe the total win you get from a really simple GUI framework is diminished.

True, once you break out into the "big bad world" of network protocols and disk I/O, your code may not be quite as dead simple, but it really shouldn't be too hard for most folks to jump from this:

  Shoes.app do
    button "PUSH!"
  end

  Shoes.app do
    stack do
      @text = para("hostnames go here...")
      button("PUSH!") { @text.replace(File.read("/etc/hosts")) }
    end
  end

  Shoes.setup do
    gem 'simple-rss'
  end
  
  require 'simple-rss'
  require 'open-uri'
  
  Shoes.app do
    stack do
      banner "News.YC Headlines"
  
      button("Fetch") do
        @articles.clear
        
        rss = SimpleRSS.parse(open("http://news.ycombinator.com/rss").read)
        
        rss.items.each do |item|
          @articles.append { para(item.title) }
        end
      end
      
      @articles = stack
    end
  end