Top priority:

• Separate mode from creative
• Allow specifying the default gamemode when creating a world #886
• Disallow commands without cheats
• Per-player modes (stored on the server)

Additions needed (in order of priority)

• Disable creative menu for survival players
• Block Breaking
• Item collection
• Added fall damage and /kill #959
• Added crouching and block based friction #926
• Swinging #953
• Rework pickaxe power/time to break a block #232
• Eating #966
• Hunger / Food Mechanics #965
• Add a system to handle status effects on the player and other entities. #624
• Procedural Crafting (Remaining Work) #89

Issues relating to the addition of Survival Mode:

• Synchronize the game mode with the server. #846
• Stamina #257
• Armor and accessories #604
• Calculate time to break a block from tool properties in survival and add a block breaking animation. #620

Entity related:

• Entity AI #86
• Entity Animation #87
• Entity Support #88
• Make it illegal to place blocks inside of the hitbox of entities #90
• Prevent Nerd Poling #851
• Drowning #933

Physics related:

• Friction and Air resistance #83
• Buoyancy #84
• Swimming #85
• Make the player coordinates wrap around at the integer limit #310

Inventory related:

• Allow blocks that store items. #78
• Improve how the inventory is synchronized with the server #643
• Item drops cannot be collected #644
• Breaking blocks doesn't drop items #645
• Improve how block placing/breaking is synchronized with the server #751
• Track item durability in inventory synchronization (needed when breaking blocks with tools) #847

Implementation Bugs:

• The creative inventory remains open and items can be taken from it when the game mode is switched to survival. #743
• Tools are created with a different seed on the server. #879
• The player "hand" inventory is not saved. #882
• The player inventory is not saved on disconnect/when the player is deinited. #883

The Finale:

• Surpass Java