The last time i felt this kind of engagement from a game was probably Half Life... back when it initially came out.
Over the years there have been many many many first person shooters all with their own niche but most focus too much on a particular aspect and even more fall afoul.

The missing ingredient - keep it simple.

The GZDoom engine gave Zan everything he needed to create an immersive world, great story line, characters you give a ♥♥♥♥ about, platforming, puzzles and of course the hardcore brutal gore at the hands of big mommy orc barbarian.
The first person shooter aspect is a fraction of the game considering you can perform alchemy, base building side quests, stealth sections, wave clear gauntlets and and you can even pet the warg.
The hand drawn art for all the character sprites and the amount of written dialogue really brings the feel of this world to life. I found my self unable to betray or sacrifice any of my sisters just because i enjoyed speaking to them.

It all comes together to a produce fantastic game that rivals the originals imo. I can see how much passion went into this game and thank the creator for the experience.