A resoundingly faithful re-imaging of Half-Life, but introduces enough new elements to feel fresh and exciting.
For the 0.5% of people out there who don't know the plot of Half-Life, allow me to give you the condensed highlights. You are Dr. Gordon Freeman, a bespectacled, bearded research associate at the Black Mesa Research Facility: A giant underground complex in New Mexico of offices, laboratories and test chambers where experiments of dubious ethical and scientific value are carried out. Freeman has a Ph.D. in Theoretical Physics from MIT and appears to be just your average scientist, until the fateful day arrived when everything was thrown out of the frying pan. At the beginning of the game, you take part in an experiment which results in a terrible disaster befouling the Black Mesa Research Facility: Massive damage is sustained and portals to an alternative alien dimension open up across the complex, with all manner of dangerous animal life stampeding through, wreaking havoc. Most of the game is comprised of your attempts to escape the facility and also to avoid the marines of the Hazardous Environment Combat Unit, who have been sent in by the US Government to "liquidate" the situation, including all Black Mesa personnel. Black Mesa doesn't alter any of the story beats of the original game, and includes line-by-line many sequences from the original game. However it does often extend dialogue and conversations by adding in additional flavour text and incidental chit-chat, all of which feels true to the spirit of the first game. As of the time of writing, Black Mesa does not currently offer a complete recreation of the original game: The levels which take place in the alien world of Xen are still to be completed. Nonetheless, this is still a lengthy game which will take approximately 10-12 hours to finish, feeling very one-to-one in terms of length with the original Half-Life.
Gameplay itself hasn't been drastically altered from the original. Freeman has access to the same arsenal of weapons, from his trusty crowbar to the MP5 submachine gun and several more experimental weapons later in the game. The enemies you meet along the rollercoaster journey are just as varied, ranging from the ubiquitous headcrabs to the HECU Marines. The shooting of Black Mesa feels comparable to the original game, but certain weapons feel either slightly more powerful or less so. For example the crowbar now has less reach and takes several hits to dispatch a headcrab, whilst the shotgun can bring down a marine or vortigaunt with a single shot at close range. All of the memorable set pieces from the original game make a return, normally with a new spin on a familiar theme, or introducing a new physics puzzle into the mix, similar to those encountered in Half-Life 2. An example for this might be you need to turn off the valve where gas is escaping in order to extinguish the flames. In the original, you'd just turn the handle and be done with it, but in Black Mesa the handle is actually missing, necessitating a brief search before you can reunite handle with lever.
Graphically is naturally where most of the time and effort of crafting Black Mesa has been invested. The game is similar in detail to the original Half-Life 2 and borrows many lighting effects from Episodes One and Two. By and large, it looks great. It's not going to win any awards for graphical prowess, but if the objective of Black Mesa was to bring Half-Life up to the standard of its sequel, then it definitely succeeded. The amount of custom geometry, taken for granted in any retail game, is very impressive, with an absolute minimum of props being imported from the standard Source list, ala Garry's Mod. There are many gorgeous high-resolution textures which have been finely constructed (my personal favourite being the health kits) and all of the character models look as good as anything Valve put into Half-Life 2. Black Mesa uses a rather sophisticated face creation system which generates semi-randomized character faces, which means you're unlikely to see the same character twice. Level design is by and large a straight up-rezzing and improvement on the original layouts, but many areas have been altered and extended for the sake of continuity. For example, there used to be a very sudden jump between the laboratory areas of Sector C to the more industrial ones, but now this change happens more gradually. Nonetheless, every room, corridor and outdoor vista feels true to form, and you will recognise many famous areas including the Hydro-electric Dam, the lobby of the Biodome complex and of course the Lambda reactor core. There are many highlights to the experience, but my personal favourite was Questionable Ethics chapter, which raises the game in terms of atmosphere by posing many questions about whether the Black Mesa scientists are as innocent as they appear, given the highly controversial experiments.
Black Mesa really excels in the audio department. The game has been fully re-voiced by a volunteer cast, all of it recorded professionally and delivered flawlessly. Some lines are a word-for-word repeat of the dialogue from the original game, but many character interaction moments have been elongated or changed to include further chatter and ambient conversations. Pressing the E key on any character will normally yield another line or two of flavour dialogue, often unique to that character. In a conscious effort to secure continuity with Half-Life 2, the named characters of Dr. Isaac Kleiner and Eli Vance feature in the game, as does security guard Barney Calhoun in the most fleeting of cameos. The musical score has also been completely redone, drawing a heavy influence from the original music but delivering something with feels completely fresh. Valve games have never been particularly acclaimed for their music, but the soundtrack to Black Mesa provides a suitable backdrop to the various hectic goings-on at the research facility.
Black Mesa does make one or two relatively minor mis-steps, the biggest of which may be the overreliance on the oft-fabled crouch-jump. In Half-Life original, you might have had to use the crouch-jump manoeuvre (jumping and crouching at the same time in order to achieve a higher or longer jump) maybe once or twice throughout the campaign. In Black Mesa, crouch-jumping is an essential skill you must master early on if you want to jump into vents, or cross gaps which are impassable using the normal jump. This can lead to occasionally frustrating sections where you make multiple attempts at the same jump, quicksaving and reloading after each try and inevitable plummet to your death. The epicentre of this frustration is definitely the trip-wire mined room in the Surface Tension chapter, which was maddening enough in the original game but is even more so here given the fact that you must crouch-jump over a laser line which you have no idea if you will hit or not because Gordon isn't body-aware (when you look down, you can't see his feet). There are also infrequent technical glitches including long loading screens and crashes to the desktop, but no doubt when Black Mesa is officially released on Steam via the Greenlight initiative, these will have hopefully been patched out.
When it comes down to it, the most amazing thing about Black Mesa is the fact that it exist at all. After 8 years of intrigue, disappointment, excitement and regret, it is incredible that a team of volunteers, paid nothing and doing all coding, designing and building off their own backs, sitting through years of whinging, moaning and apathy from the Internet, managed to create a game in the first place, let along create a game which is a great experience. Although that experience is still not truly complete, it is certainly worthy of your time, especially given the incredibly low barrier to entry. Black Mesa reminds us of everything which made Half-Life great, and yet it is also an education in what aspects of it weren't so great. Games have moved on a lot since 1998, but the core appeal of a shooter has not changed. Half-Life raised the bar for storytelling, atmosphere and action; Black Mesa can be proud to say that it can jump just as high. Now you can experience an updated version of one of video gaming's most historic titles, and it won't cost you a nickel.