On Hard mode, the reverse happens. Kind of embarrassing to show up asking for a replacement every couple minutes.
Spaceship combat is pretty fast + furious and tends to degenerate into just firing as fast as possible. But it is feasible to keep superior enemies at bay by circling continuously and wearing them down with missile fire--- the AI can't seem to figure out an intercept course. I don't have air-to-ground combat figured out though.
Also, I learned (on the Internet!) that you can restart a stage by creating a new game using the existing creature. All you lose is the history, not the bonuses.