I'm really stuck on the challenges. I've had to repeat them about a dozen times and am STILL stuck.
On the sub challenge, I can't get past level 1. That damn destroyer comes at me right off the bat and doesn't let up.
On the plane challenge, I can't get past level 2. I can hold off the first and second waves, but the third wave that comes after the shipyard always manages to get through.
On the ship challenge, I'm stuck on level 2. My cruiser usually gets wasted by the third wave of ships.
I have to admit that my grasp of naval tactics isn't very solid, but I can't believe I suck this bad. Is it me or is this game really hard? It also seems that there aren't a lot of helpful tips on ship tactics out there.