Key features:
- Smarter and more difficult mobs
- Added thirst bar and temperature bar
- Added more structures (Formations overworld, ATi structures, and towns and towers.)
- More biomes added
- More foods added (farmer's delight and Manor's bounty
Quality of Life:
- JEI makes it so that you can find and create items faster
- Better Days allows players to speed up nights if more players are sleeping
- Anvil balance limits the experience costs of combining and enchanting items.