A great, underrated game
Graphics: 7
The graphics are not really detailed and amazing, but they are enough to get the idea across about the game though. The graphics are smooth and basically clear. The enemies look pretty good, but there isn't much variety between them. Most of the levels repeat themselves, but the ones that don't have pretty imaginative environments. The only reason why I give the graphics an 7 and not an 8, 9, or 10 is because they're not excellent, just good. As long as the graphics don't interrupt the gameplay they are fine in my opinion.
Sound: 6
I know that this may seem somewhat harsh, but the sound is a little dull. The enemy sounds are okay, but are distorted and a little fuzzy at times. The sounds of the weapons are mediocre, because most of the weapons sound similar. The music is fine, but can get a little annoying at times, especially when the same sound keeps repeating itself for multiple levels in a row. This game needs more variety regarding sound.
Gameplay: 9
This is where the game shines. With the different weapons and obstacles in each level, there is always something different to do. Even though the goal is always to rescue the people who are being attacked by zombies, there is always a different way in order to reach that person in need of assistance. Some levels are just mazes, while others actually take planing and the use of different weapons to get around enemies. The idea of co-operative gameplay is also a lot of fun, especially when you play with another person and not just a computer. I don't know what other category this would fit under, but the only "terrible" thing about the game is the fact that you can't save. After a couple of levels, the game will give you a password, but it is practically impossible to start off at the higher levels without the weapons that you would have had. If you would have been able to save, then the game would be two times better. The only disappointment as far as gameplay.
Control: 8
The controls are good, and you basically have complete control over your character. The only thing which it lacks is that the shooting is not always precise. You aren't able to shoot everywhere you want, because of the D pad. You can only shoot up, down, left, right, and in the diagonal directions, nothing in between. You also have to move with a tank-like motion. This can be annoying at times especially when you have a load of zombies cornering you. Otherwise the controls are good.
Overall: 8.4
The most important part of a game is gameplay, which is what this game delivers. Without the great gameplay, this game would not be nearly as good as it is. Even though this game is not widely known, it is still a great game. It's too bad that so many people missed out on this great, unknown experience.