Shadowrun: Dragonfall is the sort-of-sequel, sort-of-DLC for Shadowrun Returns. It's available as a standalone "Director's Cut", so you don't even need to play the first one (but I would recommend that you do, I really enjoyed it). I played the Director's Cut standalone version.
The world of Shadowrun presents you with a future filled with biomechanical engineering, magic, metahumans, dragons, virtual reality and so much more. It's futuristic cyberpunk meets high fantasy, and while the geography of the world might be the same as ours, this "Awakening" has caused huge wars and a massive change to political and social dynamics. There are new empires, new city-states and new dangers, and it's up to your team of "Shadowrunners" to navigate them.
