Post Script is an interesting new mod-in-progress for Half-Life 2 by Lewis Denby:
Post Script is an episodic, interactive narrative, exploring a set of characters as they look back on the second end of the world.
A post-post-apocalyptic tale of humanity and inhumanity, Post Script examines the nature of society, how it shapes us and how it’s shaped by us. It asks how we respond to astonishing hostility and unexpected love. It raises big questions, but there’s a decent chance it won’t get round to answering them. It is, vestigially, a series of very short computer games, in which you do a lot of walking around and occasionally solve a lightweight puzzle.
– Via GamesIndustry.biz