These unlockables are accomplished by doing various in game tasks:
2K4 Team:
Record 15 double-doubles to unlock the 2K4 team
ABA Ball:
Play in 1 street mode game to unlock the ABA ball
All Atlantic Retros:
Record 5 wins with any Atlantic division team to unlock all Atlantic retro jerseys.
All Central Retros:
Record 5 wins with any Central division team to unlock all Central retro jerseys.
All Midwest Retros:
Record 5 wins with any Midwest division team to unlock all Midwest retro jerseys.
All Pacific Retros:
Record 5 wins with any Pacific division team to unlock all Pacific retro jerseys.
All-time 76ers:
Grab a total of 150 rebounds to unlock the All-Time 76ers team
All-time Celtics:
Block a total of 100 shots to unlock the All-Time Celtics team
All-time Lakers:
Steal the ball a total of 20 times to unlock the All-Time Lakers team
All-time Sonics:
Dish out a total of 150 assists to unlock the All-Time Sonics team
Bonus Street Court:
Play in 20 street mode games to unlock a bonus street court
Boss #1 court playable in street mode:
Defeat the 1st 24/7 boss to unlock his court in street mode
Boss #2 court playable in street mode:
Defeat the 2nd 24/7 boss to unlock his court in street mode
Boss #3 court playable in street mode:
Defeat the 3rd 24/7 boss to unlock his court in street mode
ESPN Ball:
Play in 5 street mode games to unlock the ESPN ball
Exploding ball:
Attain 50% unlockables completion to unlock the exploding ball in street games
Hall of Fame difficulty mode:
Attain 100% unlockables to unlock Hall Of Fame difficulty mode
Menu color 1:
Start a franchise mode game to unlock hidden menu color #1
Menu color 2:
Finish a franchise mode season to unlock hidden menu color #2
Menu color 3:
Finish and win the championship in franchise mode to unlock hidden menu color #3
Menu color 4:
Complete 15 years of franchise mode to unlock hidden menu color #4
Menu color 5:
Complete 30 years of franchise mode to unlock hidden menu color #5
Menu music 1:
Start a season mode game to unlock hidden menu album #1
Menu music 2:
Win the championship in a 14 game season to unlock hidden menu album #2
Menu music 3:
Win the championship in a 28 game season to unlock hidden menu album #3
Menu music 4:
Win the championship in a 56 game season to unlock hidden menu album #4
Menu music 5:
Win the championship in a 82 game season to unlock hidden menu album #5
Ooga Booga Ball:
Play in 15 street mode games to unlock the Ooga Booga Ball
Rock Ball:
Play in 10 street mode games to unlock the Rock Ball
Rookie Class:
Score a total of 100 points to unlock the Rookie team
SEGA Sports Challenge Team:
Record 1 exhibition game win to unlock the SEGA Challenge team
SEGA Team:
Play for 10 hours total to unlock the SEGA Team
Sophomore Class:
Score a total of 500 points to unlock the Sophomore team
Superstars team:
Steal the ball a total of 100 times to unlock the Superstars Team
VC Team:
Record 15 Triple-doubles to unlock the VC team.
Increase the difficulty of your opponents free throws:
When playing against a human opponent, while they are at the line push the L trigger repeatedly to cause your opponents controller to vibrate. This increases the difficulty of free throws.
Get all 24/7 unlockables:
When creating your player for 24/7 First Name: HUNT Last Name: 4TREASURE in all caps.