I thought I had the original game in my GOG account but it turns out I only have a clone (Xenonauts). I haven't played it at all and I bet I wouldn't have played the original XCOM either if it was in my GOG account.
The reason? I'm sad to admit that but it's the graphics. I can sometimes play older games, e.g. arcade games from the '80s or '90s, but I really struggle with most older graphics games. That makes me sad because there are some real gems that are now older than 20-30 years and I'd really like to be able to enjoy them, but I can't.
There's a time to play, and a time to admire graphics, I guess. Oh Ecclesiastes, you were so right.