Great for a beta
This game has a lot going for it: good storyline, unique gameplay, new characters. However it is lacking.
What it needs in my opinion is more levels, rather than one insanely difficult one. Give different planets... like a solar system thing to select a mission. you need better AI! seriously... the fact that the aliens chase after one guy each time is buggish at best. another thing was your human AI. needs more customization, like rewcruitable soldiers, following aliens, escape given the situation(s).
a big one: terrain! try, like on different lands, interactive terrain elements (i.e. rocks, caves, mutant shitcows)
i have a lot of ideas... PM me if you want to hear them.
8/10, 5/5