Infinity Cave adds a seemingly infinite cave system beneath the bedrock layer increasing it from -64 to -128. With this comes many new challenges and an overall different way of experiencing PvE.
Minecraft too easy? Try this mods with nearly 40 modifiers - settings new mini bosses, which made minecraft become hard & insane. Enhanced hostile mobs' AI. Zombie place/break blocks. Skeleton,Spider,Creeper,Enderman.