The 1.5.2 patch corrected several high-profile glitches that affected daily gameplay:
It lacks many modern mechanics that some purists avoid, such as natural regeneration consuming hunger, horses, and regional difficulty. Key Features & Fixes in 1.5.2 Minecraft 1.5.2 Version
Create a "New Installation" and select from the dropdown menu. Hit "Create" and then "Play." such as natural regeneration consuming hunger