Here is the full list of all 51 WWE 2K20 achievements.
UNIVERSE: Play and Win 50 matches.
Use the Adrenaline Payback to Carry an opponent over your weight class. (PLAY mode against A.I.)
CREATIONS: Create your own Arena.
Win a Royal Rumble as entrant #1 or #2 against AI.(PLAY mode against A.I.)
Defend successfully against elimination in a Royal Rumble match. (PLAY mode against A.I.)
2K CENTRAL TOWERS: Clear Roman Reigns' Tower
CREATIONS: Create a unique Superstar with their own Move-set, Entrance, and Victory pose.
Win a Title by cashing in your custom MITB. (PLAY mode against A.I.)
PLAY: Take control of a Superstar and win a Tournament against AI with "DAMAGE RETENTION" enabled.
Perform a Dual Attack in a Mixed Gender Match. (PLAY mode against A.I.)
Steel Cage: Push off an opponent from atop the Cage. (PLAY mode against A.I.)
Steel Cage: Escape through the door. (PLAY mode against A.I.)
UNIVERSE: Create a new Major Show in Universe.
UNIVERSE: Complete a year of universe.
UNIVERSE: Complete a Month of Shows.
UNIVERSE: Activate a potential Rivalry.
Finish your opponent using a possum pin. (PLAY mode against A.I.)
Play one Match using Assist Mode. (PLAY mode against A.I.)
Use Payback Low Blow to slow your opponent down. (PLAY mode against A.I.)
Use Payback Instant Recovery to quickly rise after being knocked down. (PLAY mode against A.I.)
Use Payback Spray Poison Mist to your opponent's face. (PLAY mode against A.I.)
Break free from a Carry. (PLAY mode against A.I.)
Activate the Run-In Payback. (PLAY mode against A.I.)
Hit your Finisher immediately after activating Blackout Payback. (PLAY mode against A.I.)
Defeat your opponent with their own Finisher. (PLAY mode against A.I.)
Use the Tank buff to minimize damage from your opponent's Finisher. (PLAY mode agaisnt A.I.)
As a Tag Team, perform your Tag Team Move. (PLAY mode against A.I.)
Finish an opponent without landing a finisher or signature. (PLAY mode against A.I.)
Send your Opponent through a table. (PLAY mode against A.I.)
Put your opponent through the top of the cell. (PLAY mode against A.I.)
Attack a Groggy Opponent with a Diving Attack from the Top Rope. (PLAY mode against A.I.)
Break out of a Submission without overlapping once. (PLAY mode against A.I.)
Win by performing a Pin Combo through a Signature or Finisher. (PLAY mode against A.I.)
Reverse a Finisher. (PLAY mode against A.I.)
SHOWCASE: Clear all matches.
MyPLAYER TOWERS: Complete one Tower.
MyPLAYER: Reach Prestige Rank 2.
ROAD TO GLORY: Win 50 matches.
ROAD TO GLORY: Win 10 matches.
ROAD TO GLORY: Win a Main Event in a PPV.
Use Payback Rush to steal 3 finishers in one match.
Use Payback Fortify to deflect 1000 total damage.
Equip a Favorite Foreign Object and grab it from under the apron.
MyPLAYER: Complete a Side Plate.
STORE: Open a Loot Pack.
MyPLAYER: Use a Boost in a match.
Attack an opponent with the Tripod Foreign Object (PLAY mode against A.I.)
MyCAREER: Clear Chapter 1.
MyCAREER: Clear Chapter 4.
MyCAREER: Clear Chapter 10.
MyCAREER: Clear Chapter 18.