Gameplay is a bit sharpened now, but the redicilous amount of health the aliens have kind of ruins it, and that's very very sad. I kept running circles around every enemy and emptying clips on them, that's fun at the start but it becomes VERY annoying after a while. I would suggest you drop the alien healthpoints by 50%. This way they keep above average health but still be a high threat. It's good to keep those geneticly enhanced creatures in as sort of bossmonsters, but the normal aliens really should not be like that. A gonome with 1000 health is just too much. The difficulty is high enough on the map to change this and still have a challenge on the map. Futher gameplay is very much balanced, and switches nicely between different enemy's.
I would rate this map quite high, but the Alien health issue kind of discouraged me. Perhaps you can change it in the next beta
Very good work so far !