The game now supports analog control and, as with most sports games, it's a big improvement over digital. Other improvements include players that don't wilt to the ice when you unintentionally run them into the boards, and far fewer goalie interference calls. Referees will call for a video review if they think a player may have been in the crease when a goal was scored, and the resulting calls are usually right on the money based on what you can see for yourself from the replay. There are also a wider and more realistic variety of penalties called. These are all relatively minor enhancements but, together, they add to the realism of NHL 99.
Fighting is one aspect of the game that remains unrealistic.
There are simply far too many of them. I averaged three per game in 10 minute periods. Fights seem to be limited to your two most aggressive players. Based on the one game that I played against them, Eric Lindros and Chris Gratton were the two guys always looking to rumble. Aside from the unrealistic frequency with which fights break out, they don't look very good either.