Paradise Lost is DLC for Postal 2 released on April 17th, 2015, exactly twelve years and four days after the initial game's release. After the buggy bullshit of Apocalypse Weekend and Akella completely mangling Postal 3 in the name of saving money (seriously who the fuck releases a game without an esrb rating), Running With Scissors decided, with the sudden jump in popularity the original Postal 2 had attained, to go back to it and start updating it again. This culminated in the development of a new DLC package ten years after Apocalypse Weekend's release, Paradise Lost.
The story of Paradise Lost is simple: Postal Dude nuked Paradise in Apocalypse Weekend and escaped with Champ, Champ jumped out the window during the escape to chase something, and as the Postal Dude headed back for him, his head-wound acted up again, causing him to crash into the first solid object capable of stopping a car he found. This sent him into a coma, during which he had a bad dream that he was in a poor imitation of his original weirdest week with a different voice in some place named after a cat or whatever. Finally waking after eleven years, he decides to search for Champ, the only lead he's given taking him to the ruins of Paradise.
Being DLC for Postal 2, it's inevitable that this will be compared to Apocalypse Weekend. Fortunately for it, the comparisons are for the most part much more in favor of it. It's still buggy, probably moreso than AW (have to use a specific renderer to not crash on switching zones, cutscenes sometimes play improperly or not at all), but for the most part it's much, much better - RWS decided to go with what made the original Postal 2 fun rather than throwing it out the window. It's open-world, it doesn't artificially inflate the difficulty by forgetting to place decent weapons or any medical supplies where they're actually needed, the humor is actually funny all throughout, you have actual options for most situations rather than just "shoot everyone" again (even if I'm not going to be taking them), and it is, above all, entertaining.