I wrote this free book on how to make games with Ruby using the DragonRuby Game Toolkit. As I've been learning the engine, I've felt really inspired by how quickly I can prototype my ideas and release them for all the major platforms. DragonRuby GTK is a really interesting use of mruby and SDL. To see Ruby be used for anything other than Rails is always exciting. I thought maybe this book would nudge others interested in Ruby game dev to take the plunge. Would love any feedback! Thanks.