The new gameplay style takes some getting used to, but ultimately the changes are good for the NHL franchise.
Gameplay feels a lot more similar to 2K's NHL 2K3, with the incorporation of a new control scheme. Like NHL 2K3, there's a shift button to perform advanced moves, such as fake shots and passes, or to get a player to block the puck. There are now two pass buttons, one for regular passes, and one for saucer passes. A new feature is the ability to control the direction of your checks with the right analog stick.
Once you start playing, you'll notice how much more challenging NHL 2004 is compared to its predecessors. The game difficulty is comparable to NHL 2K3, if not harder. The moves you used to pull off in previous NHL games won't work as effectively, especially if you like to make long passes or "blind" one timers, where you could make a centering pass and count on a man being there for a one timer. Quality one times are hard to come by, as usually guys in front of the net are being tied up by the defense, and passes are hard to complete. The best way to score is probably to put a shot on goal and hope for a rebound. Pucks will trickle off goalies, something that was first noticeable in NHL 2003.
The presentation and graphics are again, top notch, and complements the new gameplay quite well. The eye candy effects you expect from a hockey game are there, with ice reflections and the ice getting scraped up and losing its shine over the course of a period. You can knock helmets off players now with a hard check, but it happens rarely. By default hero stats, which first appeared in NHL 2002, are turned off, and EA got rid of the tacky gamebreaker feature, further convincing us that NHL 2004 is a serious simulation. However, if you are unhappy with the default gameplay settings, you can still tweak settings like puck friction and game speed to your liking.
If there's one thing bad about the game, it's your teammates' AI. They don't appear too bright. Too often you'll find yourself the only skater in the offensive zone, with no one to pass to. They don't recognize odd man rushes, rarely will they trail the play when you take the puck down the ice. Even when you hold the puck behind the opposing net, your teammates will not get into any good positions for you to attempt a one-timer.
The new gameplay style takes some getting used to if you're a long time NHL veteran, but ultimately the changes are good for the NHL franchise, paying off with an excellent simulation of hockey, and a solid, satisfying game.