Final mission was a bit too easy. 1 reactor, 1 physics lab, and 1 Super Carrier Starport did the trick with a couple of repair turrets just at the start.
Rather entertaining despite it's simplicity. Keep working on it. Did encounter a bug... froze up on encountering a water leaper (first time I'd encountered one). Reloaded, but still frozen.
Thanks FritzW. That's a really unusual bug, I'll send you a PM to see if I can work out what's happened.