I just wanted to pop in and say I like this game a lot. I've only played the survival mode and unlocked all the missions but man it's hard.
If anyone knows how to best survive, I'd like to know that too. I've tried to branch out early and get all the resources, get the next tech as soon as possible, and upgrade rather than build new units, and try to sell off and retract towards the base when resources run out, but I still can't get to the highest tech. My highest score is like 2000 or so.