As a kid I scantly followed UFO theories and was fascinated by the stories, but there was no real interactive way to go into the stories. Then I found UFO Aftermath. Remember, this was when the game was new, no patches, and my PC could barely run it on Windows 98. I still loved it. It also sparked my interest in military sci-fi and let me know from then on that I am a tactics game buff.
The story is great, I won't spoil any of it. It's just a good story to this day makes me wonder why a book hasn't been made like this. The glossary of weapons, equipment, and research descriptions is more than enough for any sci-fi fan and entertaining on it's own to read.
The AI is ok, not the best but you can tell certain enemies have certain preferences in combat. Cudgels seems to sneak around and hide when not engaged in combat, but as soon as they get a clear shot their lack of a brain shows and they shoot at you. Morelmen are non-sneaky versions of cudgels, etc. and all act for lack of a better word like wild rabid animals that wanna get you. But this is not a critique of the AI, as I think these are brainless creatures (a few are based off earthworms!) in the first place so it makes sense they act like they this, and may be an attempt by Cenega to simulate the behavior of such critters.
There is a ton of guns, there is a lot of equipment, and a huge global map yours for the taking. I played through a few times and it's always fun. I come up with new tactics or revise old ones, but each time I play it's never exactly the same. For a last word I will mention in the options you can choose to start in Europe or America, Europe is easier as it's more territories in a smaller area meaning less flying times for your aircraft but America is what I choose for a challenge.