Black Mesa: Definitive Edition - 17b - Interloper [Hard]

Chapter 17: Interloper - Part Two

Having finally infiltrated the Nihilanth's Tower, Freeman stumbles into a vast and intricate bio-manufacturing plant built to create the vicious Alien Grunts that he fought back on Earth. With upward being the only way forward, Gordon slowly begins his climb up the Tower, making his way past enslaved Vortigaunt workers, vats of strange alien fluid, perilous bottomless pits and gross fleshy tunnels. Unfortunately, Nihilanth's forces have detected his presence, and he must contend with their attacks as he ascends.

Playlist with all completed chapters:
   • Black Mesa: Definitive Edition (Full Playt...  

Notes:
Unlike HL1, the Vortigaunts in the facility will never attack Freeman unless directly under the control of the Controllers, even if Freeman attacks them first (2:09)
Doors such as the ones on the left of the screen at 6:21 are spread throughout the maps showcased in this video. If Freeman indiscriminately kills Vortigaunts, new ones will spawn in and come into the map through those doors. There seems to be an endless supply of Vortigaunts this way
If Freeman doesn't dispatch the first two Controllers that attack him in the pump room in time (7:19), it will punt the crumpled up pieces of fencing at him, which will usually result in an instant kill
The Controllers in the large chasm at 10:47 will never attack Freeman, even if he breaks stealth and shoots them
As opposed to using a grenade to destroy the overflow plug at 20:06, Freeman can jump onto the small platform on the bottom left of the screen and get directly underneath the plug
To my knowledge, the Nihilanth's voiceline at 21:04 is a line cut from the game (however it is present in HL1). I added it back in with the "Restored Nihilanth Quotes" workshop mod - thanks to user UGLIES for letting me know of this mod!
The Alien Grunts encountered starting at 22:10 are a different variant than the ones Freeman encounted on Earth - these ones can jump, dodge and fire a rapid volley of bees from their Hivehand, making them deadlier adversaries. They also have a greater health pool than the Earthbound agrunts, though they are still vulnerable to headshot damage. The Crossbow is a very effective weapon against these variants
The chargers that replenish Freeman's supply of depleted uranium-235 works for both the Gluon Gun and the Tau Cannon (25:00)
Once Freeman starts fighting the Controllers, the agrunts that appear at 25:41 spawn in on their own separate timer - if Gordon takes too long to kill the Controllers, he will have to contend with both parties


Trivia:
All the maps shown in this video do not call back to any particular map in HL1's Interloper; the original chapter's factory maps start off at the conveyor section, whereas Black Mesa's show the agrunts being manufactured prior to their encasement in an egg
The Vortigaunt at 0:45 disables the alarm that first detected Freeman's intrusion into the facility
Upon overloading the pump stations (5:03), if one were to inspect the pipe leading into the overloaded tank, it can be seen that the green fluid actually moves faster relative to those in tanks that have not been overloaded
There are many signs that allude to the Tower actually being a living organism, such as the fleshy tunnels and bloody stitched walls (6:53). Chris Horn, senior level designer of Black Mesa, has confirmed that this is the case
The barrel puzzle at 12:01 is often bugged, and the barrels have a chance of exploding upon contact with the water, gate or the player. In fact, this can occur later on in the map even if Freeman isn't around - loud underwater explosions in the area of the map at 18:02 can beard if this bug occurs
Freeman can softlock the game by tossing the plug at 16:19 down the shaft he initially entered at 15:21 - there is virtually no way to toss the plug back up once it goes down there. Not that I made this mistake while recording...obviously (*nervously sweats*)
The Alien Grunts that fall from their pods at 16:31 actually spawn into the pods before falling
The Alien Grunts in the pods are invulnerable to damage, as shown at 17:10
From user Pete Kustra: "The pipe sequence at 18:36 is pretty similar to the final chapter of Portal when Chell goes through the storage cube vents"
From user Mintor94: "you don't lose oxygen in [the section at 18:36] until you end up at the other end of this pipe"
If Freeman stays on the box at 20:06 when the Controllers start pulling it out of the room, he will simply clip through it and fall to the floor
The addition of the chargers to provide Freeman with limitless Gluon/Tau ammo (25:00) in this map and the remaining ones in the chapter is reminiscent of Freeman acquiring the Super Gravity Gun/Dark Energy Field Manipulator in HL2