Inside the files of this game, there is an extended line from the G-Man character, if you choose not to join him. He says the identical "Well, it looks like we wont be working together. No regrets Mr. Freeman," but goes on to comment on there being "a few survivors of your personal holocaust" who would "like to meet the man responsible for the total annihilation of their race".
Fans have created a remake of Half-Life called "Black Mesa" which uses the latest version of the Source engine. This remake has completely redone graphics, new character models, and some new voice-overs. Valve, whom are the creators of the original game, fully support this remake.
Half-Life: Blue Shift was originally designed to be an extra feature exclusive to the Sega Dreamcast version of Half Life. When the Dreamcast version of Half Life was cancelled due to the poor sales and impending death of the Dreamcast console, the game's makers, Valve and Sierra decided to release the Half Life: Blue Shift add-on for PC instead.
The Black Mesa PA system is composed of single words, instead of entire lines of dialogue. This allows dynamic creation of PA messages by level designers. Most of these single words are not used in the game proper, but were created so that independent level designers could make realistic sounding PA messages for their levels, instead of relying on default ones.
The fictional military unit in the game uses a wide variety of military vehicles, that exist today. These vehicles include the M1 Abrams Main Battle Tank, M2 Bradley Infantry Fighting Vehicle, AH-64 Apache Gunship, V-22 Osprey and F-16 fighter.
The PAL version of the game has some major drawbacks: no enemy bleeds whennl you kill them, when you kill a friendly, the don't die, but rather they sit down in sorrow and whine, and the marines in the game have been replaced with robots.