I think it may be the opposite with regards to Unity and being time constrained, as there's a lot more to learn with Unity when making games rather than something like DragonRuby Game Toolkit. For a hobby that you have only a little bit of time to dedicate to, I think 2D games in an engine with a simple API would be quite a bit easier. But that's just me!
I agree with Brett! Plus, if you're not already experienced with ruby, you'll get some exposure to the mruby variant in DR. It's been a pleasure working in ruby!
Thank you! My co-founder and I quit our jobs and moved to India 6 years ago, and we've been working in the urban Indian water space since then. We really felt that something needed to be done and we've been on a journey to figure out exactly how we can change the status quo. We appreciate all your support- it means so much!