NBA Jam Old-School Edition

2nd Demo Additional Features
Initial-entry and record keeping reenabled (although you still can't progress through the game)
10 secret players
Backboard breaking (slightly buggy)
10 more announcer catchphrases
A new music track which is played between quarters (click the YouTube video link below to listen to it)
Yet more cosmetic changes, including those seen in the screenshots posted since the first demo
Bugfix: The player injury counters were not reset after completing or quitting a game. Prior to this, if you selected the same team and player combo for the next game, the players would have the same number of injuries as the last game played. This bug actually exists in the unmodified NBA Jam TE ROM as well.

1st Demo Features (lazily copied from the readme)
135 players from the 1992-93 roster, including stars that didn't make it into any official version of NBA Jam (Jordan is in)
Complete 1992 East and West All-Star teams (includes Magic Johnson!)
Player attributes now display correctly (10 is displayed when a player has a 10 in an attribute; corrections made to some players, eg. Stacey Augmon, Dennis Scott)
1992-93 team colors/logos, except for the All-Star teams (the Eastern and Western Conference logos didn't exist until 1994)
Ability to cycle backwards through the player combos by pressing X or Y (on Team Selection and Substitution screens)
Modified Title Screen graphics/music
Many other cosmetic changes sprinkled here and there (i.e. Some players' pictures look better)
Keep in mind that this is only a demo. Many more features will exist in the final version.

Source: TheGamesDB