NHL 2004 has a deep career mode, titled Dynasty Mode. You take on the role of GM for up to twenty seasons. As GM, you'll have to negotiate contracts, conduct drafts, make trades, sign free agents, make sure your players are getting the training they need, and more. If you're good enough, you may make it into the GM Hall of Fame.
Besides Dynasty mode, you've got the basic game modes; Season, Exhibition, and Playoffs.
The control for NHL 2004 has been refined, allowing for more precise movement than in the previous games. Precise passes, shots, and accurate skating are accomplished by simply tapping the button.
NHL 2004 features a new fighting engine, allowing for more accurate and realistic fights. The right analog stick controls "Bruise Control", which lets you perform different moves by tilting the stick in different directions. Before you get into fights, you'll need to agitate a player, and this is where his Agitation Meter comes in. Losing the game, being checked, making sloppy passes all raises his Agitation Meter, until he is ready to burst and will fight at the slightest poke check.
In addition to the standard roster of NHL teams, there are thirty nine international teams for you to choose from, such as Germany's DEL or Sweden's Elitserien, plus the usual U.S.A., Canada, and other regulars.