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