X-COM is what every game wants to be when it grows up.
X-Com's is the crowning achievement for PC hybrid/genre-bending games. No other game had ever managed to combine strategic depth, resource management, rpg-ing and tactical squad-based combat into a cohesive and well-crafted package. Truly the game is amazing, even by today's standards.
By now everyone knows the story, aliens are invading earth, they are bad, they must be killed. However instead of stepping on the shoes of Captain Steroid, and shooting the hell out of the little green men, you take the role of the leader of the UN's appointed alien-retaliation unit: X-Com. The thing is, you are pretty much flying solo here. You are given a monthly funding with which you are trusted to build bases all-over the world, hire personnel, start researching alien technology, shoot down UFO's and proceed to examinate them, etc. Sounds simple enough right? Actually in a way it is, and that's probably the game's major acomplishment, it manages to blend incredibly deep and complicated (not to mention diverse) gameplay premises and merge them into a perfect amalgamation of pure genius.
When it comes to base-building you have to consider placement, defences, installations, and the like. Personnel recruitment is a mini-rpg game where each of the soldiers in the game has his/her own stats (which determine their equipment availability and their roles in combat) and must be exercised by experience, yet you have to balance each squad and have fresh recruits ready for deployment to cope with fatigue, wounds and even KIAs. And then you have possibly the best aspect of the game, which is the turn-based squad tactical combat. Combat takes place on isometric tile-based levels complete with every option now common to tactical games, such as taking advantage of cover, statistically accurate firing models and more esoteric options like sneaking around, sniping, etc. etc.
The research aspect of the game brings into the spotlight another sexy aspect that X-Com blends in succesfully: Alien lore. This provides more than just an interesting setting for the game, but also serves as the perfect means for gameplay progression. Once you salvage enough equipment your technology tree will start to grow, but more importantly so will your options. Having better airships will allow you to take down bigger UFOs (in yet another great mini-game) which in turn means bigger challenges and greater payoffs, new weapondry (like tanks) will change the rules of the game, and eventually psychic research will yield even more tactical considerations in the squad-based portion of the game.
Yet the game doesn't just rely on that gimmick to progress gameplay, with each success and improvement you make the aliens will take notice, and soon enough you'll go from shooting down tiny UFOs to big motherships, and the aliens will start to terrorize more and more cities (which add human hostages to the mix). Then you'll start discovering alien outposts and bases and eventually they'll discover one of yours and try to invade it, and that's where the base planning takes part (that and the reserve of soldiers you remembered to keep around.... right??). Eventually you'll take the action off-world in hopes of clearing the alien threat once and for all, but that my friend, is another story :)
How can one put this without sounding like a rambling fanboy??? Well I just can't. There's absolutely nothing wrong with X-Com. All I can think about is that for the "idle" moments on tactical mode they should have added a real-time mode to accelerate things, but that's it.
Oh, and sometimes it can become overwhelming in it's open-endedness and options, but I chalk that up more to my poor attention span than the game itself :)).
The Bottom Line
Well, let's put it this way: If some bad-ass aliens come and blow the hell out of earth ending thousands of years of human evolution and cultural development, one of the many things we'll be able to think about while we are torched out of existence is "Well, at least we had X-Com out of the deal!"
Without a shadow of a doubt X-Com is one of the most imaginative, innovative, and well-crafted games ever made. A pure example of gameplay perfection and refinement. Truly a masterpiece among masterpieces and a must in every serious gamer's collection. If you haven't played it you simply are not a gamer, you are just an average jerk with a computer :) Now go, it's time to show that damned Alf who's the boss.