Black Mesa has an elusive 'Rarest Specimen' achievement that takes quite a few steps to accomplish. This guide will lead completionist toward accomplishing this goal.
Being a remake of Half-Life, Black Mesa was developed by the third-party developer Crowbar Collective. Valve was experimenting with Half-Life: Source, which was a redesign of Half-Life using the Source Engine. According to fans, it lacked anything innovative. So the team 'Crowbar Collective' was formed and they took the initiative full-time and totally rebuilt Half-Life from the ground up with a revamped campaign. Based on where the game takes place, this remake was titled Black Mesa and it takes fans of Half-Life on a familiar adventure with a classic hero.
Related: Where To Find The Secret Hidden Hat (Rare Specimen Achievement)
Black Mesa was commercially released on March 20, 2020 and it's a first-person shooter with players taking control of Gordon Freeman. Freeman is a theoretical physicist that works in the Black Mesa facility that's located deep underground. While on the job, Freeman was tasked with placing an ominous material into an anti-mass spectrometer for analysis on its properties. Naturally, something went wrong and it caused an inter-dimensional rift that destroyed the entire facility and caused an invasion of beings from a dimension called Xen. Players will have to fight their way through the Black Mesa facility while encountering all manners of threats that range from; environmental hazards, alien lifeforms, and military personnel.
How To Get 'The Rarest Specimen' Achievement In Black Mesa
After players obtain the 'Rare Specimen Achievement' in 'Chapter 14. Lambda Core', the 'Rarest Specimen Achievement' will automatically stack on it after continuing the campaign and finishing the game. In order to do this, the purple hat will need to be carried all the way to 'Chapter 18. Nihilanth.' This is arguably the most difficult achievement to get and can be a tedious task. However, there are certain spots to place the hat throughout the course of the remaining game that'll free the hands of players. When the weapon is holstered, players can walk (or sprint) while holding the hat. So, Gordon Freeman can move around fairly nimbly while in possession of the hat which eases the burden during platforming or in combat.
- Chapter. 15 - Xen
After jumping through the portal at the end of 'Chapter 14. Lambda Core', players will find themselves in 'Chapter 15. Xen'. It's important to note that there is scarce ammo in Xen, so be mindful of Freeman's firepower. Also, keep a trip mine handy, as players will need them later on. At the beginning of this chapter, players won't have the hat in their possession, they will need to re-locate it later on. Toward the end of this chapter, players will go through a small portal in which they will be transported to an edge of a platform. Once this happens, look to the left, and players will notice an island floating nearby. This is where the hat will be located. Make way to the island, pick the hat back up, and far-jump back to the main area.
Progress through the chapter and whenever players encounter 'Leaf Doors', just leave the hat in front of the door and make way through it. Clean out the area, then go back to retrieve the hat. Don't drop the hat into the 'healing pools', because there's a glitch that makes it impossible to pick it back up. Also, when navigating over the fallen tree branches, do not place the hat on the branch because it'll fall off. Just keep-longing jumping until players reach solid ground. Eventually, players will fight their way into an interior section that will a series of puzzles to solve. Just leave the hat in the control room, complete the puzzles, then go back to the control room and retrieve the hat. By now, players will be ready for Chapter. 16.
- Chapter. 16 - Gonarch's Lair
Once this chapter begins, players will find themselves in rugged, rocky terrain. Suddenly, Gonarch will show up to give players a hard time. Blast him with rockets and he'll retreat to fight another day. After this encounter, proceed through the chapter. It's fairly straight forward with a lot of flat surfaces to place the hat for safety. Whenever combat arises, drop the hat and take care of the problem, then grab the hat and proceed. This also holds true when traversing through the bog. Drop the hat, then snipe the barnacles that are in the way, then keep carrying on with the hat. Afterward, a water section will need to be completed. It's possible to complete this entire section by letting go of the hat and letting it "sink" to the bottom of the water pit.
Once this section is finished, just dive back into the water and bring the hat back to the surface. Players will ultimately travel deeper into the lair, where the showdown with Gonarch will commence in a large area. Before starting the fight, place the hat in the 'center' of the arena, and take care of Gonarch. Toward the end of the fight, the 'center section' of the floor will collapse and everything (including the hat) will fall to the lower levels. The fight will become more intense and Gonarch can easily knock the hat to unreachable places if players aren't paying attention. The main focus here is to keep him away from the hat until he'd defeated. After the fight, there will be shattered crystals strewn about all over the place. Players will need to scour the area until the hat is found, again.
- Chapter. 17 - Interloper
During the beginning, players will need to throw the hat up onto the third-level of the area. If it glitches and gets stuck in mid-air, just shoot it with a pistol and knock it loose. Make way up to the upper-levels and continue to carry the hat. As always, when a shootout happens, just drop the hat someplace safe and go back after it's clear. Eventually, players will enter an interior area that has steam jettisoning out of the walls. Make sure to face the hat toward the direction of the steam and don't let it get stuck on the edges while in the vents. Mid-way through this chapter, players will come across a "control center" section that has large, extraterrestrial cables protruding out of the walls. There's a barrier in the way so, place the hat in a corner somewhere and make sure it can't fall off any ledges. Players will need to take out some aliens in order to clear the barrier and continue the journey.
Players will then need to climb up a vertical segment in order to get out of this area. On the wall, there will be a large vent with steam hissing out. Throw the hat into the vent, then jump into it. A narrow, claustrophobic, platforming section will need to be completed. The platforms are small, so keeping facing the hat 'up' and zigzag the way up to the top. It's best to 'quicksave' after every successful attempt of landing on each platform, just in case. Once at the top, there will be a 'Xen Factory' that'll have a large skirmish waiting for players. Drop the hat at the opening pathway that leads into this area and clear the area out. Players will circle around and make their way back to the hat. The area will now be clear and walking with the hat will be much easier.
The next area of the factory will have conveyor belts with pods on them. Leave the hat at the corner of a small 'control panel'. Clear the area then go back to pick up the hat. Then, players will come across a sealed up vent to bust through. Do not shoot open the vent, because it'll suck the player to the next section, without giving them the chance to pick up the hat. Instead, take the trip mine (that was hopefully saved) and place it on the vent. Pick up the hat, walk in front of the vent and the mine will detonate, sucking Gordon along with his hat to the next section. After that, players will encounter a large generator-type of device. Inside it, will be a spinning cylinder which is a good place to hide the hat. Take out the alien controllers in the area then go back to retrieve the hat. Keeping moving until Gordon walks onto a strange, intricately designed lift. Carefully, place the hat anywhere so it won't fall and keep fighting until the lift reaches the top.
- Chapter. 18 - Nihilanth
The next step is perhaps the easiest part of this achievement. Walk up to the portal and throw the hat into it. Jump into the portal then defeat the Nihilanth. After the last battle, players will then see the 'G-Man' wearing the purple top hat on his head. This is when the achievement will be unlocked. Players can try and obtain this achievement on their first playthrough. However, it's recommended that players try to get this achievement on their second playthrough to make things easier for themselves. Thus, playing the game on the easiest difficulty will also be a good way to go about this achievement.
Black Mesa is available for Microsoft Windows and Linux.