Flesh out the DragonConsole a bit more to get it closer to IRB.
I'm dependent on return values and line editing, I'd really appreciate getting the full overt and implied feedback from every command and the ability to edit a line rather than backspace through it.
I was going to make this separate, but we need some sort of hyperlinked help. An ri-like command in the console would be great, but at least some formatted docs with an overview of the API pieces so I'm not studying the samples to (poorly) infer functionality. It took me about 6 hours to grok the 3 x,y parameters in a sprite (I was approaching it as absolute value stretching) and I'm still not convinced I have the parameters sanely labelled.
(I'm super stoked about you adding Hashes, that will resolve a lot of my derpiness)
Viewing post in Posts feature requests here!
Reference source code for the console. Maybe see if it sparks some ideas? https://github.com/DragonRuby/Game-Toolkit-Symbol-Lookup/blob/master/dragon_console.rb
The key takeaway here is GTK's developer support stuff is built with GTK.
And from a philosophical standpoint: no matter how good the HUD becomes, you will eventually out grow it over the lifetime of a non-trivial game. "Batteries include" tool chains are really great getting started, but it doesn't show the dev that it's just as "easy" to extend the tool chain and tune it such that it "grows" with the application being built.
I'd encourage you to make your own HUD that's customized/optimized for the work you are trying to do (I definitely looks like you have a grasp of advanced Ruby concepts and I think you'll make some really amazing things).