Here is the full list of all 12 METAL GEAR & METAL GEAR 2: Solid Snake achievements.
Complete Boss Survival in Metal Gear 2
Read all the pages in the Screenplay Book
Complete Metal Gear 2
Defeat Big Boss in Metal Gear 2
Defeat Gray Fox
Destroy Metal Gear D
Complete Boss Survival in Metal Gear
Complete Metal Gear
Defeat Big Boss in Metal Gear
Destroy Metal Gear
Start Metal Gear
Start Metal Gear 2