Nimpex

Includes changes to generation (caves and new biomes in both the overworld and the nether), new mobs, adds seasons, new structures, new health system, new backpacks, more items for sleeping, new auditory and visual enhancements, GUI changes, new blocks,  performance enhancements (new lighting engine changes, mob culling, and other small tweaks), new leveling system, mouse tweaks, and new artifacts to find in naturally generated chests.