I've already hit a wall after 2 weeks where I can't progress without buying a lot of keys and hoping I get really strong energy multipliers, kind of getting bored.
Alright I finally managed to beat that final mission, what I did to kill the raze soldier was run into him and make him suicide otherwise he would take too long to kill, static field is good but so is cloaking so you can set up stealth kills on the humans and not take damage.
You'll be hard-pressed to find a better community :) -Ray