Excellent game, still it can be better.
I strongly recommend it.
What I still want from it:
More variate landscapes and items (tactical phase).
More challenging fights. (I didn't need to use cover, crouch or stealth a single time). The aimed shot is also useless and I also didn't launch a single rocket.
Assaulting fixed strong defensive positions should improve the use of all of the above.
Shooting down alien crafts is also fun and I miss it.
And, because you stare so much at the Red Planet surface, a little more graphical details and terraformation changes can only improve the feeling.
But these are merely details... the game is rock solid... waiting for the sequel:))