I continued my first playthrough (livestreamed on Twitch) of Extermination during late January 2022, and I finally beat the Executioner boss! (It took me a few tries! It turns out you can do the best job up close and personal with the knife weapon!)
Afterward I climbed a snowy mountain (and fell off a bunch of times accidentally, haha!). And then we reached what I thought may have been the end boss (our good buddy Roger) which turned out was the second-to-last boss! Afterwards I traveled back into the main compound, to get ready for the final sequence leading up to a crazy end boss fight!
Technical Reference: I captured the game using the RetroTink 5X-Pro (available at the below link) coupled with an ElGato HD60S+ capture card with RGB output from a Playstation 2 slim (running the original Extermination game disc). https://www.retrotink.com
There are 280 views in 8 videos for Extermination. His channel currently has around hours worth of content for Extermination, or 4.69% of the total watchable video on DJRebirth's YouTube channel.