When reaching to the mod's finale, I found out it was ridiculously unbalanced even on the easiest difficultly due to the Tesla supersoldat.

I'm not sure how people managed to overcome this, and some may figured it just the same, but I found a way to cheese this last part by standing in the left passageway to the other room, where the Tesla soldier remains static and you can only see a portion of its body, allowing you to shoot it safely, or at least doing enough damage until the Tesla gun is disabled and the soldier switches to Gatling gun and rockets, making it a bit easier to kill it.

See image:
https://imgur.com/a/XSbs6Yq

Note:
This is only relevant until the author, if ever, decides to fix this problem, just as many people complained about.