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