Logically shorter, but with more intense action which makes it better than the original.
The plot itself does not shed enough importance to the original game, but it gives you enough sense of being there and executing given missions and objectives such as rescuing a downed pilot and hunting down a North Korean container, supposedly carrying a nuclear warhead, hence the name of the expansion. The game uses cutscenes, which are used to good effect at forwarding the story at a faster and more understandable pace. If you haven't played Crysis, there isn't so much of a necessity of knowing about the events in that game, since the ending of Crysis Warhead does not do any significant change in the overall Crysis storyline.
In contradiction to the previous game, the nanosuit is not placed into the spotlights. The nanosuit itself is a special designed suit that you wear and it gives you superhuman abilities, such as increased strength, increased defence, increased speed or a special cloaking ability that makes you invisible. You can use only one ability at a time, and the usage of them is limited by a special bar that is indicated below your health bar. This gave Crysis a different variety of gameplay, you could have sneaked through different enemy locations and retrieve intel without being noticed or stormed through the territory, killing everyone that stood against you. It's not like that in Crysis Warhead. While you still have the option to use all these abilities, the game's waves of enemies and fast pacing makes it almost logically mandatory for yourself to be constantly in attack mode. Which is a good thing, since the action is intense and fun.
A sufficient array of weapons is given to you to choose from, where you can hold only two main weapons and a pistol. Since this is an expansion, the number of weapons is not fairly large, but you'll find yourself sticking to a good weapon for a long time through the game. Feeling of the weapons is just right and there haven't been any changes to them, which is a good thing, since they still do give you a powerful feel when you wield them, some more, some less. The AI you face is boiled down to two types. The North Korean army and the aliens you encounter early in the game. The alien AI is improved, where they take cover from you and attack in more organized groups. The North Koreans on the other hand aren't so much advanced and will only slightly annoy you when you won't know from where you're being fired at. But in the end, you making yourself invisible gives you the edge over them sometimes. The AI difficulty will increase towards the end of the game, making the experience even more dramatic and intense, but you'll still be able to finish the job. Overall the combat is the best point of Crysis Warhead, even more satisfying than the graphics, since your main focus will be on killing waves of things than looking at the pretty scenery.
From a graphical standpoint, the game can still be beautiful to admire, if you hardware can support the maximum settings, but the developers have done a good job at toning down the demands for the minimum reasonable computer requirements, that still make the game look pretty decent. Every other component that makes up the environment you play in, is fleshed out decently and gives you a nice organic feel to the game.
While the original Crysis showed off more of its graphical advancement and nanosuit concept, Crysis Warhed simply shines in action and combat. Even if you haven't played the original Crysis, this is a must buy for any fan of the first person shooter genre, adding the fact of the low price, superb graphical and physical environment.