GJ, that`s good game to play! 
Im sorry but I uninstalled game before completing it, for various reasons. Main reason is because, although game is great, but it lacks atmoshpere and anticipation, as I could quit game any moment without feeling any particular motivation to keep playing. Anyway I have bad PC, so, although game runs fine, but there are many places in game where it really starts lagging. I quit game at end of "Questionable Ethics", where bunch of soldiers comes down from helicopters and I couldnt shoot them due to heavy lags.
Anyway I dont have free space on my HD partitrion where my steam folder resides, so I had to get rid of something for sake of installing and trying other games. If it wasnt for that, then Id still be trying to get past that part. However thats where that first reason plays a role- lack of anticipation in game, so I really felt no motivation to keep playing to see what`s next.
Now, let me switch to review. Although I didnt complete this game, but graphics and level design are amazing. Models are amazing. Weapons looks amazing as well. However Im not sure what exatly caused this lack of anticipation of game, but I suspect its because gameplay itself wasnt that enjoyable. For following reasons:
-Because some weapons didnt feel very good: *my favourite weapon, magnum had unnaturally high recoil, so shooting with it lacked satisfaction; *its impossible to fire single shots with mp5, or it was due to my bad pc, idk. As I try to tap, multiple bullets are shot regardless. I dont like spray and pray style, so I didnt like that game denies my attempts to fire single shots with mp5.
*there is no feel of damage when opponent is beign hit, other than pain sounds. Its a common "paintball shooting disease" between fps games and Black Mesa suffers from it a lot. -I dont like that A.I., despite how strong it is, is very vulnerable and lets its guard completely down when it dont see player. Its like I can blow up a atom bomb in one room and guys in next room wont notice anything. -Fighting agains soldier A.I. is feels more like chore than fun experience, as they just starts spraying at you and so your only opinion is to take them down as fast as possible, to recedieve less damage. Of course, its possible to react faster than them and kill them before they react, however only after I have figured out theyr positions on map and reload save, witch feels so discouraging, because the first experience should be most fun, but instead in game reloading save is more fun, as beign low on health is hardly enjoyable on unforgiving hard game.
-volume of soundtrack is completely screwed up. Most of songs are 3x or even louder than sound in game.
-it feels as developers lacks basics of storytelling. To make game exciting and to develop anticipation while playing, a buildup is neccesary. However game feels like running through designed levels without feeling any anticipation.
-teleporter sound. Original sound was very distinctive, however teleporter sound in BMS lacks this charm.
Anyway, as for what I can praise developers for:
-graphics, level design, models, voice acting, dedication, game! Thanks!
-I really like basic combat mechanics of Xen creatures, because they, unlike in original games, are more dangerous and theyr behavior cant be exploited as much as it was possible on original games. Vortigaunts were hard as theyr attacking speed was so fast, so it was a exciting to fight them and it really added sense of danger. Houndeyes always manages to damage me when on close range, so I had to use any means neccesary to put them down before they can get chance to cast theyr shockwave, witch really added sense of danger. Bullsquids arent weak anymore and if in original half life theyr spits could be avoided easily, then in BMS they`re faster and bigger, so to dodge them I really had to focus on timing instead of casually observing the tiny spit pieces coming my way as it was on original game.
No score, because I quit halfway. But awesome work! 
p.s. I just remembered. Ah, nostalgy, why such things aren`t in Black Mesa Source as well… (original soldier pain sounds - “oh, Derek”, etc)
" and then they all spreads away and bam bam bam bam bam. Also their accurateness that wasn’t the same as HL1. They were accurate,because they are pros. In HL1 they were just some bastards walking around with a little gun shooting around with no thinking of their life at all. In BM they just shoot everything and anything (with exception of the other him,of course) because they were clean up crews. I also love how blood splats to your weapons and hands when you shoot something close up. They also add more “reasonable” split up with another guys such at when OC,the Scientist refused to jump and sits when the Guard stands and cover him. Or at FAF when we open the pipe and the Guard stays to figure out another way.