Half-Life: Extended is an unofficial mod for the popular first-person shooter game, Half-Life. The mod is free and adds a number of new features to the base game in order to extend the playability.
Being released in 1998, and superseded by Half-Life 2, Half-Life is no longer being worked on by the developers, but still has an active fan base. Half-Life: Extended adds things like new weapons, maps, and other content to the game, giving fans another reason to play the game again.
Half-Life: Extended adds new content to the game, including new weapons and enemies, new maps, increased NPC variety and diversity, raised difficulties, and the restoration of content that had previously been cut from the game. Some of the maps in the game have even been recreated from scratch in an effort to reimagine the base game.
This mod is a cooperative project, and the developers behind it have provided an SDK to make it easier for other modders to make content for the game. The team behind this mod has focused on the first four chapters of the game, so that is where the largest changes can be seen, though improvements and additions can be found in other parts of the game as well.
The large amount of additional game content will make this mod appealing to fans of the original Half-Life game. However, the dated graphics and gameplay may make this less attractive to people who were not already fans of the series to begin with.