oh my, i didnt know there is a hypenated and non-hyphenated version specifically. I am referring to the initial one, the one
Yes, that is X-COM. If you don't have much experience about such games, I recommend you to start with XCOM: Enemy Unknown (or Enemy Within). It has good tutorial, less soldiers on the field (in X-COM: UFO Defense it can go up to 20, maybe even over), and probably less aliens per deployment. Cover system is easy to understand and soldiers & aliens can do some sensible stunts, like jump over small obstacles and open the door from the side where wall provides cover. Simply put: XCOM is beginner friendly while X-COM can be overwhelming. X-COM with all its faults is better game, and OpenXcom makes it even better (get it if you haven't already).
What comes to myself, it isn't easy to make a choice from good games. So I'll get them all. Xenonauts and X-COM collection are in sale over at Steam, so why shouldn't I grab them all for dirt-cheap while I still can? I'm gonna start with Xenonauts, then move on to X-COM series reinforced with OpenXcom and OpenTFTD. I'll get back to UFO: Alien Invasion when it is ready & done ( = isn't patched anymore). UFO: Extraterrestrials is said to be bottom performer, so I'll ditch it.
You know what they say, don't you? About how us MechWarriors are the modern knights, how warfare has become civilized now that we have to abide by conventions and rules of war. Don't believe it. MekWars