this mod adds obsidian level 2 and 2 new structures and one new challenge and new recipes or crafts and other things and soon will be added secret dimension and secret biomes and strange mobs that have strange names but it will be soon so to say in the future but secret wolrds has version 1 for now and version 1.1 is supposed to be in the future and maybe it will be a huge update and all that and soon will be added these other things
