EDIT: After several rounds of updates and whatnots, they've released a weirdly named standalone version (I say "weirdly named" because it needs Doom 2 iwad, but hey) that bundles 2063, Dead Man Walking and Afterglow. For some reason is only in their new moddb page.

Think on Metro 2033 meets John Carpenter's Escape movies, meets Fallout, meets STALKER in a Doom 2 Total Conversion where you play as a Scavenger in post-apocalyptic USA.

The original chapter 1 has been updated on this Enriched Edition which features not only several improvements on the (already amazing) mod but also the "expansion"/fan map pack "Dead Man Walking".

The sequel/chapter 2, named Afterglow has been released just today, and, as the developer mentions, is to be expected to have bugs, so maybe is better to wait a bit (And that's why chapter 1 is there).

Now, I have nothing to do with this mod, but I played original "Chapter 1" when it released, and was completely blown away by the quality of this game, so the release of the sequel/chapter2/whatever is going to be a highlight in my October.

Also, it should work "as is" if you put the pk3 of the file in your GZDoom directory together with the doom2.wad file and following the standard practices to play Doom 2/GZdoom mods.