It's iconic!
The only reason this game didn't get 5 stars is because it was outdone by its successor. I love turn-based tactical RPGs. It's my thing! And XCOM sits at the very tip of the heap.
The art direction is outstanding and the story (campaign?) is engaging. And the fun thing is, even though you know the routine, it's never the same game twice. You can play the way you want to test your skill of tactical warplay to no end.
The character design is awesome. The perks and reward system work fairly well. I remember how difficult it was to get used to in the beginning because it was my first XCOM (X-COM) game; ever. BUT once I got the hang of it, the dollars spent to hours played ratio got ridiculously one-sided.