While visiting 2K's booth at E3 2010, we had the good fortune to check out XCOM behind closed doors. It's definitely a change from the original games, as it's played entirely in first-person. It also takes place far before any of the past games, which were set at the turn of the Millennium, while XCOM occurs during the 1950s. With these changes, a new developer, and a new generation of technology, will XCOM stay true enough to the originals to maintain its fan base?
One thing that sprang immediately to mind was Fallout 3. Having been a third-person isometric game, the change to first-person, at least in most people's eyes, definitely did not hurt the series. They do keep a lot of the features from the originals, such as your base of operations, letting the player pick and choose which missions are taken, either completing missions for money, Alien resources, or just to help the population. There will also be a lot of researching in order to create new weapons from Alien technology. Unlike Fallout 3, however, XCOM will be a series reboot, so fans will want to expect some liberties will be taken as far as story and minor details are concerned.
We were shown a short gameplay video where the main character, "William Carter", and two unnamed agents enter a suburb to save a family being attacked by the aliens. It did seem a little odd that it all took place during the day, especially given the emphasis on fear the game is taking, but once the aliens are seen for the first time, it became more like a chase scene. After clearing out the Aliens, we were attacked by a floating, geometric shape-shifting creature called a Titan, which was very creepy. As the weapons needed to fight it hadn't been obtained yet, our only choice was to flee.
Though it looks and feels very different from its predecessors, XCOM still looks very promising. You can tell the developers want to do the series justice, but adapt it to modern technology and tastes. There's still no release date planned, but this ain't your pappa's XCOM.