Review
Defcon 5 tries to take the first person genre to new heights by blending story and strategy with lots of shooting and killing. While the idea seems nice at first, the execution leaves little to be desired.
Your basic objective is to stop an inevitable alien encounter/invasion aboard a space ship. The best thing about this game is the story and it's development. It's pretty intriguing at times and it's just unfortunate that it doesn't have a good game to go with it. While every other game in the first person shooter genre would have you going from level to level kicking some serious alien butt, Defcon 5 does things a little differently. In certain areas, you'll have to log on to an intranet console computer and run test data, find out what missions need to be taken care of, unlock certain doors, search for information, so forth and so on. Unfortunately, this aspect hurts the game. The interface is far too cumbersome and confusing and it's really frustrating. And when you find out where you need to go, it's pretty hard to get there because of the less than exciting or cohesive level design. It's not particularly inspiring and only proves to be rather confusing. A lot of the same textures are used many times and it's just way too hard to get familiar with the levels. You'll find yourself wandering from corridor to corridor looking for the room you need to go in or the item you need to pick up. There's nothing that really tells you, "Okay, you're not supposed to be here," or, "Yes, you are here!" It just lets you roam and roam the halls until you happen to stumble upon where to go. And then there's the actual graphics engine itself. While the framerate is pretty solid, Defcon 5 just doesn't feel right. There's absolutely no feeling whatsoever; it seems "empty".
Fortunately, the control is okay and shooting the various aliens and creatures you run into are pretty cool. Sometimes when you kill enemies, they'll emit harmful gasses and change the air quality of the room. This proves to be pretty strategic because you have to think about how you have to kill certain enemies. But you have to take everything else into consideration while playing this game. You have to do the console interactions and spending half the time being lost on the spaceship is just really frustrating and these two things are the reason Defcon 5 isn't appealing. The developers were trying to do something different, but it just doesn't work here.
Graphics 
Some textures get used way too much and the overall look of the game leaves little to be desired. The robots and aliens you fight have pretty poor animation and it's just not appealing to the eyes.
Sound 
The sound effects are pretty decent and the soundtrack is solid.
Enjoyment 
Because of the confusing level design and horrible console interaction sequences, Defcon 5 isn't very fun at all. And while the actual shooting aspect isn't too bad, I found myself wanting to play something else.
Replay Value 
There isn't much reason to play this game in the first place. There are better games out there and the actual gameplay doesn't have enough oomph to hold anyone's attention for a very long time.
Documentation
The manual is pretty average, but it tells you how to play the game.
