Duke Nukem:Zero Hour is an extremely fun, action packed blast!
The thing I like most about the game is the level of action, and the attitude. The beginning sequence is action packed, and really presents the character of Duke as being one bad dude. The game has really, really great "Dukespeak". One of the things that made Duke 3D so popular was that Duke would talk while you played. There are tons of awesome, funny things that Duke will say throughout the game. There are lots of references to movies that make the game even cooler, and every time you meet a boss, Duke will say something interesting to it. There are also cool cinematics on the beginnings of most of the levels.
Duke has a pretty big collection of weapons to use in Duke Zero Hour. There are different weapons available in the different time zones. For example, in New York Duke uses shotguns, futuristic blasters, grenade launchers, etc. In the old west he can use .45 peacekeepers, gatling guns, and more.
There are also many interesting enemies to fight throughout the game. They include pig cops, an octabrain-like enemy that shoots out mental energy blasts that confuses the player, lizard enforcers, zombies and many more. There are 4 totally awesome boss fights in the game, as well.
The graphics are colorful and good for the N64. They can be improved to high-res using the 4 megabyte expansion pack for the N64.
I played the multiplayer for countless hours. There are lots of models to choose from that are unlocked as you move through the single-player mode. It goes up to 4-player split screen. The different characters have different weapons and health. They've got strenths and weaknesses. Some of them start out with 75 health and machine guns, while others have 100 health and regular weapons. There are also some odd, interesting characters in multiplayer that I won't spoil here, but they're very cool!
The game has a lot of value because of it's unlockables system. The multiplayer characters are unlocked through just completing the levels, but other cool modes and cheats are un-lockable if you do well enough on the levels. Some cheats want you to save all the babes on a certain level, while others might want all kills. With 22 single player levels including 2 secret ones, and 14 multiplayer levels, the game is pretty long, which is a good thing.
The music in the game rocks, too. The level music is great, and I like the enemy/weapon sound files very much.
Overall, this is a masterpiece that shouldn't be missed. It's an A++ game.