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