I finally have to turn here for help... I just don't get Gamma 3, where you have to assist alpha (?) units...
I wiped the map clean but the timer still ticked. So I discovered a greyish black transporter, sitting in the farmost north west upper corner. I figured that must be the reason the stage didn't finish. But I went to shelling it for 20 minutes with everything I had and it still doesn't get destroyed.
So, everytime I start schelling it, throwing everything but the kitchen sink to it, but the timer just dies and I get "you were defeated"
What am I missing?