Beta HUD
HUD modern elements and combat indicators are simplified to the effect of Beta. The XP bar is grey so as to blend in when you don't need to look at it. Sword swipe and cooldown indicators and simplified and damage indicators removed.
Hellish!
The original look and feel of the Nether. gloomy hellscape. just as it was :)
Main menu
The original main menu, dirt background included. Conforms properly to your GUI scale and window size. The "play tutorial level" button is cosmetic, clicking the button will take you to the Realms interface.
Beta GUI
All interfaces modified to respect the Beta look, in addition, the recipe book icon is hidden until hovered and tooltips are a translucent black color. Text labels are reverted to their Beta contents. Durability bars use their original colors.
Biome colors!
Grass and foliage refer to colors typical of Beta, "tall" grass colors vary randomly even within a biome, as they did in Beta.
Lighting :D
Enjoy all the features of Beta lighting; colorless, static, torches are darker and the sun is brighter just like before. Best enjoyed at "moody" brightness.
Retro-graded!
Modern interfaces are stylized to match, most noticeably the recipe book, which takes a page out of legacy console :)
Beta atmosphere!
Beta fog, water color, and sky color. Fog behaves accurately to how it did in Beta no matter your setting.