History NightmareFuel / BlackMesa

** During the "Surface Tension" tunnel part, if you think the cars strewn around the road you take as you escape the Gargantua that's literally '''[[RightBehindYou right on your ass]]''' chasing you down will slow down the Gargantua, think again, it easily runs right through them as if they were children's toys! Thank goodness that Tactical Map was there outside the tunnel...

* During the "Surface Tension" tunnel part, if you think the cars strewn around the road you take as you escape the Gargantua that's literally '''[[RightBehindYou right on your ass]]''' chasing you down will slow down the Gargantua, think again, it easily runs right through them as if they were children's toys! Thank goodness that Tactical Map was there outside the tunnel...

* If you thought that Gargantuas were scary in the original ''VideoGame/HalfLife1'', you'll be absolutely terrified by how they look now (see the page image).

** Unlike in the original ''Half-Life'', [[NoSell they are also completely immune to explosions or Gluon energy]]. Which means aside from scripted events, ''they're completely invincible''.

* Shooting a zombie so the headcrab flies off reveals that what the headcrab does to its poor victim is nothing short of ''horrifying''; while ''Half-Life 2'' and its expansions toned down the horror and just had a regular civilian model with their face in rictus and matted hair beneath the headcrab, ''Black Mesa'' goes far, far beyond that. The victims skull is torn open and the upper half is missing, and the brain is visible, and the skin is mottled, gray and decomposing.

* Also, that guard who got gunned down by a Black Ops chick? This time you can hear him gurgling on his own blood before he dies. And no, [[MortonsFork you can't save him at all]].

* Very early on there's a bit where you find a zombie attacking a scientist and, apparently, eating his face. If you kill the zombie and then examine the scientist with your flashlight, you'll see that his eyes are still moving.

** An additional emergency broadcast is added, expanding on the two that can be heard earlier in the game. Unlike the previous two, this one is a ''nationwide alert'' about the rapidly-worsening Xen incursion, informing the player that the government has been forced to resort to some ''truly drastic measures'' to try and contain the situation.
--->'''Emergency Alert System:''' The following message has been transmitted at the request of the United States Department of Defense. This is not a test. Today at 4:16 PM Mountain Time, [[OhCrap a state of emergency was declared by the President of the United States]]. An [[AlienInvasion unknown hostile force]] was declared present at the Black Mesa Research Facility, and several other locations in the surrounding areas of Black Mesa, New Mexico. As of 5:42 PM Mountain Time, [[GodzillaThreshold the President has issued executive orders to withdraw all ground forces, and begin immediate airstrikes over the Black Mesa Research Facility and surrounding areas beginning no later than 6:42 PM, this evening. For your own safety, an immediate evacuation order has been issued to the entire state of New Mexico]]. To all residents of New Mexico and surrounding areas: leave all your personal belongings, take a battery-powered radio, and only essential supplies with you. Do not remain in your homes. Seek shelter at your nearest military zone outside the state of New Mexico and await further instructions. If you cannot find your nearest evacuation route, seek assistance from local authorities immediately. [[LoweredRecruitingStandards If you have military training, firearms training, or any similar weapons training, contact your nearest military officer immediately.]] Stay tuned to frequency 740 AM for further updates on this emergency.
*** The sheer FridgeHorror of the Xenian aliens spreading beyond Black Mesa and into New Mexico is very nerve wracking. If Black Mesa, a government facility with a population of hundreds if not thousands of individuals had so many deaths, how many people were dying once the Xenian aliens began spreading across the United States?
** In an epic fight between the Xen forces and the HECU, it looks like the marines are getting the better of the exchange, thanks to the tank they are using on the alien horde. Then a nearby radio calls in an alert of "enemy air support" and you get to see a Xen Manta Ray, harmless flying pods in the original game (to the player and only before Interloper), shooting out a [[DeathRay gigantic plasma ray from its underside]] that utterly obliterates the tank and even leaves a still present trail in the pavement. Even worse, you get to hear the tank pilot's frantic screams of "BACK UP! BACK UP! [[CurseCutShort BACK THE FU--!]]" over the radio as the beam ploughs straight toward him.

*** And shortly after ''that'' you stumble through an abandoned, makeshift field hospital, while in near-total darkness and with bodies everywhere. [[NothingIsScarier Although you'd expect to be swarmed by enemies at any moment]], you only encounter scattered headcrabs and a few fresh zombies. Your relief quickly turns to horror when you realize the [[PuppeteerParasite headcrabs]] must have been drawn there by the incapacitated men and the prospect of easy prey. It's all too easy to imagine what the WIA soldiers must have experienced; trapped in the dark, unable to move or fight, in intense pain, alone except for the cittering and moans at the edge of their hearing, and their only remaining hope being that [[BetterToDieThanBeKilled they die from their wounds]] [[FateWorseThanDeath before the monsters reach them]]...

** It also doubles as fridge brilliance as to why Gordon was able to make such an effective stand against trained Marines and aliens, despite being a civilian; the HEV ''deflects'' 9mm bullets and even shotgun rounds, simply bouncing off the reactive armor of the suit. With that attribute, its no wonder the HECU had so much trouble containing and engaging Freeman.
** At first glance, you might be confused about why all those HEV-clad scientists took off their helmets and left themselves vulnerable to headcrabs, right? After all, Gordon himself is usually shown without the helmet and all headcrabs could do to him are chip damage. Well, if you kill one, take a closer look at a dead ZEV's head, especially if you manage to knock the headcrab off of its corpse. [[https://media.discordapp.net/attachments/592596745494593536/615286752013451281/unknown.png You'll find an HEV helmet's remains]], with its top side completely busted and torn off with [[SarcasmMode a lovely view of]] [[{{Squick}} the victim's exposed brain]]. That's right, ''not even an HEV suit's helmet'' can save you from a headcrab's zombifying latch.
*** On a related note, the helmets and gas masks of ZECU (HECU Headcrab Zombies) which first appear in ''Power Up'' and are promiently featured in ''Surface Tension'' didn't save them either. Upon closer inspection of said zombies' corpses, distorted gas masks and helmet fragments are shown where these soldiers' heads once were.
*** The more common Scientist and Security Guard Zombie variants which first appear in ''Unforseen Consequences'' are just as horrifying.
*** The Scientist Zombies have varying facial horror, whilst the Security Guard Zombies head has been completely ripped apart with the jaw having been ripped apart like a spring trap.
*** The fan made add-on, [[https://steamcommunity.com/workshop/filedetails/?id=2068862348 Black Mesa Character Expansion]] adds in more staff variants around Black Mesa from the other Half Life games. The mod also adds in more Zombie variants to creep you out.
*** The creepiest Zombie variant from the add-on are Cleansuit Zombies which first appear in ''Blast Pit''.
*** Just like the ZEV, not even protective Cleansuits could protect the unwillingly scientist from being latched on by a Headcrab.

** Remember the "Sand Barnacle", the cut enemy from ''VideoGame/HalfLife2''? The Xen levels themselves introduces a new enemy called a "Beneathacle" (which is technically an ''aquatic barnacle'') that can grab you as you try to jump over it and suck you underwater (Thankfully, the Beneathacle is much easier to detect and defeat due to its colorful appearance and more blatantly-visible tongues compared to the regular counterpart), which can be especially terrifying if there happen to be ichthyosaurs in the area too. It doesn't help that ammo reserves have been reduced greatly, so the lack of crossbow ammo means there's all the fewer ways to deal with them safely.

* The lot of the Vortigaunts - or Alien Slaves, as they were known in ''VideoGame/HalfLife1'' - is made bleakly clear in Xen. Some of them are living in a shanty town in the lower, Lovecraftian wastes of the Nihilanth's tower, where they are brutalized by the apparently mindless Grunts. These are the lucky ones. The rest can be found further up, [[SympatheticSentientWeapon being made to twist their own kind into the self-same Grunts that dominate them]] and wage the Nihilanth's wars. At the first sign of trouble Controllers can appear and psychically compel them to do their bidding. It's a horrible, hopeless existence, and no wonder they view Freeman as a kind of messiah figure in ''VideoGame/HalfLife2''.
* The leadup to the Garganuta chase in "Interloper". The blood-red lighting and deafening silence, especially after the [[SceneryPorn dreamy ambience and beautiful colors]] of the previous levels, is deeply unnerving. You hear the Gargantua stomping around above you before you see it, but you can't get to it. Then, you're funneled through claustrophobic canyons, never able to see much ahead of you, before a Gargantua bursts out of a "nest" along your path. Then you run, and more keep coming. ''They don't stop coming after you'' until you reach the end... and you can turn back to see them standing on ledges out of reach, roaring at you. Brrrr.

* One disturbing feature about ''Black Mesa'' is the sheer amount of [[LateToTheTragedy fresh dead bodies]] of Scientists, Security Guards, HECU Marines and Xen Aliens you'll find in the game. And did we mention the [[BloodierAndGorier dismembered limbs lying around in pools of blood?]] Everywhere nook and cranny of Black Mesa is filled with death and destruction that you narrowly missed. This certainly applies to ''Surface Tension'' where you encounter hallways and tunnels filled with the bodies of HECU Marines, Xen Aliens and Security Guards caught in the crossfire that you narrowly missed.

* One disturbing feature about ''Black Mesa'' is the sheer amount of [[LateToTheTragedy fresh dead bodies]] of Scientists, Security Guards, HECU Marines and Xen Aliens you'll find in the game. And did we mention the [[BloodierAndGorier dismembered limbs lying around in pools of blood?]] Everywhere nook and cranny of Black Mesa is filled with death and destruction that you narrowly missed. This certainly applies to ''Surface Tension'' where you encounter hallways and tunnels filled with the bodies of HECU Marines, Xen Aliens and Security Guards caught. It's a very disturbing moment on both ends.

* One disturbing feature about ''Black Mesa'' is the sheer amount of [[LateToTheTragedy fresh dead bodies]] of Scientists, Security Guards, HECU Marines and Xen Aliens you'll find in the game. And did we mention the [[BloodierAndGorier dismembered limbs lying around in pools of blood?]] Everywhere nook and cranny of Black Mesa is filled with death and destruction that you narrowly missed.

* One disturbing feature about Black Mesa is the sheer amount of [[LateToTheTragedy fresh dead bodies]] of Scientists, Security Guards, HECU Marines and Xen Aliens you'll find in the game. And did we mention the [[BloodierAndGorier dismembered limbs lying around in pools of blood?]] Everywhere nook and cranny of Black Mesa is filled with death and destruction that you narrowly missed.

* One disturbing feature about Black Mesa is the sheer amount of [[LateToTheTragedy fresh dead bodies]] of Scientists, Security Guards, HECU Marines and Xen Aliens you'll find in the game. And did we mentioned the [[BloodierAndGorier dismembered limbs lying around in pools of blood?]] Everywhere nook and cranny of Black Mesa is filled with death and destruction that you narrowly missed.

* One disturbing feature about Black Mesa is the sheer amount of [[LateToTheTradegy fresh dead bodies]] of Scientists, Security Guards, HECU Marines and Xen Aliens you'll find in the game. And did we mentioned the [[BloodierAndGorier dismembered limbs lying around in pools of blood?]] Everywhere nook and cranny of Black Mesa is filled with death and destruction that you narrowly missed.

* One disturbing feature about Black Mesa is the sheer amount of fresh dead bodies of Scientists, Security Guards, HECU Marines and Xen Aliens you'll find in the game. And did we mentioned the [[BloodierAndGorier dismembered limbs lying around in pools of blood?]] Everywhere nook and cranny of Black Mesa is filled with death and destruction that you narrowly missed.

* One disturbing feature about Black Mesa is the sheer amount of fresh dead bodies of Scientists, Security Guards, HECU Marines and Xen Aliens you'll find in the game. And did we mentioned the [[BloodierAndGorierdismembered limbs lying around in pools of blood?]] Everywhere nook and cranny of Black Mesa is filled with death and destruction that you narrowly missed.

*** The sheer FridgeHorror of the Xenian aliens spreading beyond Black Mesa and into New Mexico is very nerve wracking. If Black Mesa, a government facility with a population of hundreds if not thousands of individuals fell, how many people were dying once the Xenian aliens began spreading across the United States?

*** The sheer FridgeHorror of the Xenian aliens spreading beyond Black Mesa and into New Mexico is very nerve wracking. If Black Mesa, a government facility with a population of 1'500 individuals and not counting how many HECU marines died, how many people were dying once the Xenian aliens back spreading across the United States?

*** The creepiest Zombie variant from the add-on are Cleansuit Zombies which first appear in ''Blast Pit''. Just like the ZEV, not even protective Cleansuits could protect the unwillingly scientist. Thankfully, many of these new Zombie variants that appear in BMCE are easy for Gordon to eliminate.