
My experience was only moderately encouraging, and that was before RubyMotion was out. I think if I were to spend another weekend on it, I'd go for RubyMotion.
But I'm not likely to have a free weekend to spend on this topic soon :( If anyone wants to get Gosu to work with RubyMotion, I would certainly love to help out. I think it boils down to creating an Objective C wrapper around Gosu (something that I have done before for MacRuby), and its interface as seen by RubyMotion should be as similar to "normal" Ruby/Gosu as possible so that code is compatible.