Prequel for Half-Life. Mod allows to look and take part at the events before the Half-Life. You assume the role of Dr. Gordon Freeman. You will meet Kleiner, Vance, Barney, Rosenberg and others characters.
Although is a good effort to introduce the plot of Half Life, doesn't have any continuity to me. We see nice reskinned characters that are crucial in HL2 plot, but the plot in this mod and its dialogues lacks interest. The alternate between russian and english voices screws the experience of feeling this mod as a real prequel. The puzzles and gameplay are way too plain, so I was never really engaged to them.
If you are really interested in the story of the entire Half-Life saga, this mod could be somewhat noteworthy. Otherwise, I would pass of this if I were you.