The players are modeled pretty decently, but they do not have the polish of today's better PSX games. There is a definite lack of detail that will be hard for today's gamer to take. Some players look pretty much like their real-life counterparts, while others really do not. Given the limited power of the PSX, this is somewhat understandable, but other games, most notably EA Sports' NBA Live Series, do this much better. Player movement is done pretty well, even if it has been done better in the past.
Players look okay getting up and down the court, and the passing and shooting animations are fine.
There is no slowdown, and the animation is very smooth for the most part. The courts are very nice, with the appropriate logos and markings. You have the crowd noise, the squeaking of sneakers, the swoosh of the net and the clang of the rim. NBAB2K is done by Greg Papa and Doc Rivers, and it is pretty standard fare. On the other hand, they do a pretty good job of keeping up with the action, something that many sports games cannot claim.