There have areas in the world, and upon entering them, there is a message in the text saying: "Entered level [1-10] area," and the higher the level, among other things, the greater the size, HP, and attack damage.
Screenshots!














Also spiders like to spawn with villagers and witches riding them, which is awesome


Also the health bars are cool, and I saw a skele launch a npc villager very far, and it was funny