The details:
Metal Gear Solid: GZ is set in 1975, while The Phantom Pain is set in 1984.
In true MGS fashion, infiltrating Camp Omega can be achieved in a number of ways.
Snake's binoculars can be used to tag enemies, allowing users to see them on their mini-map. The feature can be turned off in the options menu.
Guard AI patterns are "wider and [more] unpredictable" than in previous games.
Players can fire weapons from both a first and third person perspective.
Line of sight shooting is well polished, with the playtester able to shoot between the wires in a barbed wire fence.
Inventory management is done via the d-pad - earlier inventory system is gone.
All found weapons can be used.
When escaping foes, an onscreen numerical indicator is no longer used. Instead, a directional indicator similar to Far Cry 3 is used.
An enemy's level of alertness no longer depletes via a counter. Users will need to observe and keep an ear on intercepted radio.
A new ability allows the player to slow down time briefly when discovered by a guard. This allows time to quickly shoot the guard. This can be deactivated.
For melee attacks, a button prompt appears when Snake is close enough to an enemy. Snake can select between 'interrogate', 'knock out' or 'kill'.
Selecting interrogate can force the guard to reveal locations for ammo and secret passages.
Vehicles take some time to learn. Turning radiuses are "pitiful".
Ground Zeroes comes with "a handful of extra missions".
The game features leaderboards.
Playtester completed the story mission in less than two hours.
Konami speedrunners have completed the game in five minutes.
MGS V looks "slightly" better on PS4 than Xbox One.
Unlocking side missions requires the player to collect XOF patches. Collecting them unlock the special, platform-specific missions.
Konami and Kojima Productions in November released a 12-minute gameplay video of Metal Gear Solid 5: Ground Zeroes running on PS4.