Here is the full list of all 42 WWE 2K15 achievements.
2K Showcase - Complete "Hustle, Loyalty, Disrespect".
2K Showcase - Complete all objectives.
2K Showcase - Beat "Hustle, Loyalty, Disrespect" on Legend difficulty.
2K Showcase - Complete "Hustle, Loyalty, Disrespect", 11/20/11 Survivor Series on Hard or higher.
Win a match by a leverage pin. (Single play)
2K Showcase - Complete 50% of all objectives.
2K Showcase - Complete "Hustle, Loyalty, Disrespect", 7/17/11 Money In The Bank on Hard or higher.
2K Showcase - Complete "Best Friends, Bitter Enemies".
2K Showcase - Beat "Best Friends, Bitter Enemies" on Legend difficulty.
2K Showcase - Complete "Best Friends, Bitter Enemies", 8/25/02 SummerSlam on Hard or higher.
Successfully perform a hot tag during a tag match. (Single play)
Win a match using a Desperation Pin. (Single play)
WWE Universe - Play and win WWE World Heavyweight Championship 3 times. (Single play)
Perform a giant swing with an OMG! Moment. (Single play/Exhibition)
Perform The Shield's triple powerbomb. (Single play/Exhibition)
Beat Big Show using Rey Mysterio on Hard difficulty. (Single play)
MyCAREER - Complete the tutorial.
Make an opponent tap out with a submission that is not a Finisher or Signature move. (Single Play)
Put your opponent through the announce table via any means. (Single play/Exhibition)
Hit an opponent with a foreign object or put them through a table. (Single play)
Win a match without reaching Stamina Level 3. (Single play)
Earn all achievements.
WWE Universe - Defeat Undertaker at WrestleMania using a custom Superstar.
WWE Universe - Play and win 180 rivalry matches.
WWE Universe - Play and win 50 matches.
WWE Universe - Win WrestleMania main event as the Royal Rumble winner. (Single play)
Strike or wrench an opponent in 5 different chain hold positions in 1 match. (Single play)
Eliminate 12 opponents with the same Superstar in a single Royal Rumble match. (Single play)
Win in 20 match variations. (Single play)
Win with 50 different Superstars. (Single play)
Defeat John Cena using one of the NXT Superstars.
Win 10 times using a custom Superstar.
Earn 1000 points or more playing in a single ranked match.
Win 50 ranked matches.
Reach mid-carder rank playing ranked matches.
Upload some kind of user created content once.
MyCAREER - Win the WWE Championship.
MyCAREER - Earn an overall total of 1,000,000 VC.
MyCAREER - Reach SmackDown.
MyCAREER - Have 5 attributes reach a value of 80 or higher.
MyCAREER - Complete the NXT part.
MyCAREER - Participate in WrestleMania, Royal Rumble, SummerSlam, and Survivor Series.