If I had to pick my favourite video game series, it would probably have to be Grand Theft Auto. If, on the other hand, I had to pick my favourite computer game of all time, it would be UFO: Enemy Unknown. This was an old PC game from 1994. I remember having the demo long before the actual game and playing it over and over again. It wasn't a big demo, placing you in command of half a dozen poorly armed (and unarmoured) X-Com troops at an alien "terror site", trying to save the civilians from a greater number of better armed aliens - and, above all, trying to survive.
The demo was excellently balanced - challenging but possible - which in part accounts for how I could play it over and over again. The game itself was amazing, despite some minor irritations like having to equip your squad from scratch for each mission - tedious when the number of soldiers you could deploy increased. It also seemed a bit cruel sending out the rookies in nothing but their grey jumpsuits!
The best thing about UFO, though, was the atmosphere. The tactical missions oscillated between the nervous tension of Alien and the gung-ho craziness of Aliens. (Helped in part by one of the most fearsome aliens (the "Chrysalid") looking like the Alien and even turning hapless victims into zombies that would (not much) later hatch into fully grown Chrysalids.) The soundtrack fed the tension and as the game progressed, the aliens got ever more powerful. They would also react to squad movement as you discovered them. Nothing quite made one jump like an unlucky soldier stumbling on a heavily armed foe who gunned him down instantly - a scream and then darkness as the line of sight granted by the now-deceased was lost. Storming UFOs was particularly dangerous (at least until you could make your own doors with advanced explosives).
UFO spawned quite a few sequels, which improved various gameplay components - X-Com: Apocalypse probably has my favourite tactical combat system of all time - but none of them ever re-captured the atmosphere (or scary aliens) of the original. Until now.
X-Com: Enemy Unknown for the PS3 has gone back to basics and rebooted - nay, perfected - the series. Squad size is strictly limited, harking back to that very first UFO demo, although I am glad to see that the raw recruits at least have a bit of standard body armour this time. (Not that it's of much help against the alien plasma weaponry.) The old isometric turn-based tactical missions are back but with a reworked (and better balanced) control system and much improved graphics. It may not be the most realistic game in the world (would you really only send six soldiers to take on the alien menace?) but that matters not because whatever it lacks in realism, it has one thing in abundance: fun!
The old atmosphere and fear for your soldiers is back - enhanced by having so few - and whilst the visual range of your troops is unrealistically limited, it makes for a much tenser and trickier playing experience. No longer can a bunch of marksmen sit miles from the action and pick off all the aliens with impunity. (Well, snipers can to some extent, but I'll get to that.) Instead, you have to stalk your foe, flitting from cover to cover and trying to outflank them, whilst they do the same in return.
I won't give anything away about the plot but another thing that has changed is that the game is a little more story driven, with a few more key advances and events that occur along the way to keep things progressing. A couple of other changes have made even bigger improvements in my book. One is the diversity of missions: in addition to the alien abductions, "terror sites" (rescuing civilians) and UFO missions, there are now hostage rescues and bomb defusing missions too. Even terror sites have had a facelift and now you have to actively seek out and save civilians before the aliens get them.
The biggest change, though, is in the soldier experience and upgrade. The older games featured different stats that improved with experience and depending on the balance of a particular soldier you would choose whether (s)he was best suited for heavy weapons or sniping. In the new version, there are four different classes that your soldiers are assigned to once they have a bit of experience: sniper, assault, heavy or support.
As well as giving them access to different weapons and equipment, the different classes of soldier also develop different skills as they get promoted through the ranks. There's sometimes a choice of two skills you can give them at each stage - so each soldier gets customised to some extent. (You can fully customise them in terms of name and appearance too if you wish.)
These skills really add an extra tactical dimension to the combat. Many of them have "cooldown" periods between use, so you have to select your moment. (Some weapons too are single shot.) Above all, they really let you tailor your squad to your own combat style - and, to some extent - to the mission.
One last change worth mentioning is that the game is over much faster than the original, which is good. I have already completed it once on the entry-level difficulty (unlocking a few more options for the next game) and never reached the occasional boredom of the original when hunting down another small UFO whilst waiting for the more exciting missions. Highly recommended.