One of the things I really like about Xenonauts is those little moments of unscripted, emergent drama. An example:
Very early in my campaign, on one of my first ground missions, I didn't really know what I was doing and was being much too aggressive and reckless. It was an industrial map, and two of my soldiers were sweeping a warehouse. I was pretty sure it was empty and was just quickly sweeping through it. Both of my men were on a second floor catwalk, heading towards a door. I advanced them as far as they would go until they ran out of time units (didn't even crouch them) and then hit End Turn.
Oh no! The door opened and a Caesan appeared through it on to the catwalk. My guys didn't stand a chance! Aaargh! Suddenly, there was a sound of smashing glass and the Caesan was plastered with a hail of bullets. Dead, it fell to the floor. What was that?
My heavy weapons soldier had reaction-fired his machine gun from seemingly half the map away, along an unbelievably unlikely line of sight up from ground level and through a second floor window. He had saved my guys. What a hero!
Little moments like that just seem to come straight out of an action movie, and are so much better for not being scripted but for just happening. Awesome stuff!