Here is the full list of all 13 NBA 2K Playgrounds 2 achievements.
Score 20 Self Alley-Oops
Score 33 or more points in a single round of a 3 point contest
Buy 25 packs of any kind
Reach Playoffs in the season mode for the first time
Improve one legendary player to Gold level
Suit up a player with 1 vanity item
Buy 1 pack of any kind
Activate Hot Streak by scoring 4 consecutive shots
Score 20 Double Alley-Oops
Win the season for the first time
Win the NBA Season with 1 team from each conference
Reach user level 50
Win the NBA Season on NBA difficulty