Here is the full list of all 50 Metal Gear Solid HD Edition: 2 & 3 achievements worth 1,000 gamerscore.
Complete all VR and Alternative missions
Complete all Snake Tales
Collect all dog tags
Hear Johnny's bowel noises in two locations
Find all 64 Kerotans
Find every type of camouflage
Find every type of face paint
Obtain title of MARKHOR
Finish game without killing anyone
Finish the game on any difficulty
See all of the first-person views that are not indicated by the RB button icon
Defeat The Boss
Defeat Shagohod
Defeat Volgin in a fist fight
Defeat The Sorrow
Defeat The Fury
Achieve a camouflage index of 100%
Catch a Tsuchinoko (mythical serpent)
Defeat The Fear
CQC Slam a guard and knock him out
Break the neck of 30 enemies
Complete Boss Survival
Beat the Tanker and Plant chapters on any difficulty
Defeat Solidus Snake
Defeat Metal Gear RAY
Find Emma Emmerich
Defeat Vamp
Destroy the AV-88 Harrier II
Defeat Fatman
Take a clear photograph of the ghost image in Hold No. 2
Send Otacon a picture of the marine with no pants
Attain grip level 3
Get caught by Otacon stimulating yourself
Disorient an enemy with a cloud of smoke from a fire extinguisher
Beat 30 enemies unconscious
Complete a VR or Alternative mission
Tranquilize 100 enemies
Meet Revolver
Defeat Olga Gurlukovich
Kiss a poster in a locker
CQC Slit an enemy's throat
Defeat The End
Kill The End before the boss battle
Defeat The Pain
Create the Ocelot Time Paradox
Submit Ocelot
CQC Hold up an enemy
Make Snake throw up
Eat a snake of any type
Capture any animal alive