Back in Minecraft Indev, there was a theme you could choose called Hell. The lakes were lava, there was no grass, and the sky was red. I tried to recreate the Indev scenario as best as I could in 1.12.2, even down to the excess amount of mushrooms and flowers. I'll have some links to videos as well as where you can download the Indev version for yourself. In this mod, I couldn't add a new hell theme when you create a new world, so I decided to have it be a separate dimension. The frame is made of netherrack and the igniter is Quartz and Steel, Made with 1 quartz and 1 iron. This idea was given to me by anbuotaku on minecraftforum.net. (I'll give a link to the original forum page below). I found it really interesting, as I didn't know this even existed in minecraft Indev. Thank you for checking out my mod!
Indev Hell Video: https://www.youtube.com/watch?v=zFMD9d21aTo
If you want to play the original Minecraft Indev, Follow the instructions below. Please be careful while moving files around to be sure not to lose anything.
Link to download Minecraft Indev (provided by MineCralex) http://www.mediafire.com/file/d4h0l4633sbuequ/indev.zip/file
Simply extract the file, and move it to your versions folder in your .minecraft folder. You have to turn on historical versions in installations before adding it. | I strongly recommend making a backup of your saves folder. (the folder with all of your worlds) Copy the folder and paste it into your desktop. Once you've done that, delete the saves in your .minecraft saves folder. (not the backup one) This should prevent Minecraft Indev from trying to read the newer version files. Once you are done playing indev, Move the backup saves folder back into your .minecraft folder.
NOTE: If forge stops working after you've replaced the saves folder or run Indev, Just take all the mods out of your mods folder and move them somewhere else. From there just run forge without any mods. After it opens, close it down and replace the mods. It should work fine now.
Original forum post by anbuotaku: https://bit.ly/2MGszlW