Universal Features:
-Orange sky
-Thick, moody fog
-Purple clouds
-Transparent water
-Accurate bed and shulker coloring
-Old potion particle colors
-Clean block animations
-Unique Jellie cat texture
-Consistent quartz bricks texture
-Improved block rotation
-Textured piston arms
-Consistent door and map items
-3D chest inventory icons
-Fiery launched fireworks
-Consistent water bottles
-Fixed miscolored pixels
-Pumpkin Minecoins (and other minor menu changes)
-Deferred Renderer and Ray Tracing (RTX) support for sky and lighting
-Java and Console Aspects compatibility
-Music player integration
-Legacy Console UI panorama support

Halloween 2015 (Mash-up Style) Exclusive Features:
-Cohesive grass textures
-Unique stained glass textures
-Unique wool textures
-Transparent birch, spruce, and dark oak door textures
-Many other texture changes:
  -Oak Planks
  -Birch Planks
  -Oak Log side
  -Stripped Oak Log side
  -Birch Log top and side
  -Stripped Birch Log top and side
  -Spruce Log top
  -Stripped Spruce Log top and side
  -Jungle Log top
  -Stripped Jungle Log top and side
  -Acacia Log side
  -Oak Door
  -Birch Sapling
  -Bookshelf
  -Coal Ore
  -Block of Redstone
  -Block of Lapis Lazuli
  -Block of Iron
  -Block of Gold
  -Block of Diamond
  -Block of Emerald
  -Dirt
  -Mycelium side
  -Cobblestone
  -Mossy Cobblestone
  -Sandstone side
  -Cut Sandstone side
  -Chiseled Sandstone side
  -Brick Block
  -Obsidian
  -Crying Obsidian
  -Jack-O-Lantern face
  -Redstone Lamp on and off
  -TNT side and bottom
  -End Portal Frame side, top, and eye
  -Potato crop (stage 3/4)
  -Peony
  -Rose Bush
  -Campfire items
-Natural sculk and Nether stem animations
-Accurate Mash-up world panorama
-Added missing menu textures
-Deferred Renderer Only: Green-tinted block light

Halloween 2013 (Classic Style) Exclusive Features:
-Overhauled menus
-Monster-centric paintings
-Normal Minecraft music
-Spooky Nether panorama
-The following blocks are no longer animated:
  -Dandelion and poppy
  -Green and pink wools
  -Cactuses
  -Glowstone
  -Nether stems
  -Sculk and sculk vein
-Classic pillager texture