If I was making that mod, it would be with an effectively locked seed (ie the whole world is built on one seed for everyone, so no variation).
This would then leave block-block interactions, which could just about be scripted.
Finally, you've got the 'alive' mobs, and a lot of that could be done with NPCs, animals, and magic.
After all that, you've got the general look and feel right, and if you push it further, you'll be eaten alive by copyright lawyers.
Also, about the extra-legitimate copy, I hadn't actually even heard of minecraft back then (it was a while ago), and I was assuming it was some potentially crap flash-type game that just had silly DRM. If I decide I want some software enough to bother getting it, then I usually can be bothered buying it, or at least getting it in some sale at a later date. I don't, however, like buying 2 copies of a game for no good reason, which is why someone may struggle to find my original Star Wars Battlefront 2 NTSC disk, but will easily be able to find my PAL copy if they know where my PS2 games are.
This would then leave block-block interactions, which could just about be scripted.
Finally, you've got the 'alive' mobs, and a lot of that could be done with NPCs, animals, and magic.
After all that, you've got the general look and feel right, and if you push it further, you'll be eaten alive by copyright lawyers.
Also, about the extra-legitimate copy, I hadn't actually even heard of minecraft back then (it was a while ago), and I was assuming it was some potentially crap flash-type game that just had silly DRM. If I decide I want some software enough to bother getting it, then I usually can be bothered buying it, or at least getting it in some sale at a later date. I don't, however, like buying 2 copies of a game for no good reason, which is why someone may struggle to find my original Star Wars Battlefront 2 NTSC disk, but will easily be able to find my PAL copy if they know where my PS2 games are.
OS: Windows 10 64 bit Professional
CPU: AMD Ryzen 5900X
RAM: 16GB
GPU: Radeon Vega 56
CPU: AMD Ryzen 5900X
RAM: 16GB
GPU: Radeon Vega 56