DR is an excellent tool for fast, primarily programming based game development workflows for 2D games. Hot-reload, Ruby, and ease of building & shipping to multiple platforms are some of the stand-out features for me.

Don't expect it offering all the bells-and-whistles you might need directly though; you will have to implement a lot of things yourself, although the extensive sample collection already gives you a lot of the things you will end up needing (cameras, particle systems etc.).