the concept of this mod is so interesting. kinda reminds me of how new civilizations build over the ruins of previous civilizations who are long gone, like we are seeing the remains of what once was

"Scary" mods often fail because they don't understand the limitation of their own medium, focusing almost entirely on atmosphere like this mod does is absolutely the right way to go and they seem to really understand what they are working with, they use that limitation to their advantage.
The feeling of "abandonment" was already present in old versions, then they use the way you get there to prime your brain for believing somethings wrong, and then they reinforce the feeling through expanding the already lonely atmosphere through subtle queues
It's very smart game design, allowing you to form the idea yourself and then nurturing it. Makes it very organic as opposed to forcing you to feel one way through cheap jumpscares, which although invoking an instinctual fear response, don't cause the actual emotion of fear for any length of time.
all that's to say I admire the ingenuity

This reminds me of season 2 of minecraft story mode where a huge premise was that there was an entire world below the bedrock, because the antagonist covered the previous one with the bedrock and built a new world on top of it

Your hunger bar is gone, and you can't even sprint... Imagine going to another world, and your biology just completely changes. And it's not even like you got turned into a blatantly different species or anything! You're still completely human, just changed on the inside in these few small yet very noticeable ways.

Imagine how freaky that must feel.

Can you please continue the wonderland series? I find it so comforting and entertaining watching you play that mod, I don’t know how to explain it but I like the way you play Minecraft 😂 especially the wonderland because you are not like screaming or overreacting on everything or just trying to get like clips or rushing the mod, you go with the flow of the history you explore you talk about the things your theories and everything anyway if you want come back with the series please.

Mod developer here! Ferit forwarded me your video (Alpha Below hasn’t been on my watch radar due to new projects). It’s less a horror mod, but we added horror features to keep people out of our hair about it 😭🙂‍↕️ I’m glad you took the time to check it out, I look forward to other content from you 🎉

the minecraft logo structure slowly fading in from the fog was slightly terrifying

In my restless dreams, I see that server…

Dialko has managed to essentially be a modern version of a letsplay youtuber

Experiencing mods that make the game feel intentionally old is some of the most fun I've ever had playing Minecraft recently

I agree with your sentiment that it does become very calm and serene the longer you're in the "Underworld" and it makes exploring this long forgotten world a peaceful experience

A lot of the time it kinda annoys me when mods "pretend" to be old minecraft and add old features and textures but run on the latest version, but here they did something much better. Really cool mod!

10:54 it was the body of the person who had built that house and owned a few pickaxes.

Maybe there's something wrong with me, but the snowy biome in the dark looks really cozy and comforting

The weird nether portal in the Minecraft sign made me think of how originally, the dimension was going to be called the Slip. I wonder if the mod could do something interesting with that, where if you build a Nether portal in the Alpha below world, it instead takes you to the Slip, which for all intents and purposes could just be an Alpha version of the Nether

it's terrifying to know that while I play my modern minecraft world, Dialko is just below the bedrock

Really love the idea of a forgotten Minecraft world basically frozen in time. You get to revisit the past, but no one’s there.

Imagine an expanded version of this mod that added multiple levels you could go down and it just went to an earlier version of the game each time. I'm sure it would be a coding nightmare, but it could be fun...

I know it's technically a technical/effort limitation, but I like the idea that things leftover from modern minecraft (deepslate, iron ore chunks, stacking foods, and so on) are a result of taking the new world into the old one. The player is affected, because they're constricted to the limitations of the world they occupy (no sprint/hunger bar) but the world itself and everything from it is attached to its place of origin. Deepslate can't look different because it's from its own realm. Old items have their appearance changed to that of their original, pure form when they return to their domain, because they still have that essence and history present in them. It all really adds to the vibe of feeling displaced. Somewhere you're not supposed to be, or at least somewhere the world as you know it now doesn't belong.

5:48 I actually remember seeing the whole idea kinda come to life! The mod was inspired by a twitter post someone made imagining older minecraft versions being buried under the bedrock as new versions came out, like layers of sediment, with Alpha being the main example. Hence, the mod focused on Alpha