Mod based on the leaked Half-Life 2 episodic mappack that is restoring many cut maps, scenes, models and other content of the Half-Life 2 episodes. Currently the mod has test maps made by Valve for gameplay experiments of the next HL series game, "beta maps" of the Half-Life 2: Episode One and maps made by mod's developers where you can try cut and experimental weapons, functions and scenes.

The authors are: Lever Softworks

Installation:
Extract the folder 'HL2-Aftermath' to your /steamapps/sourcemods/ directory. Then, restart Steam. It will appear in your Steam Games list as "Half-Life 2: Aftermath"

Note: This mod requires Source SDK Base 2013 Singleplayer. The branch does not matter.
Note: This mod also requires Source SDK Base 2013 Multiplayer.

ModDB page