Fun Game
The only thing I don't like is that after you beat it and you redo the levels, all your research seems to be maxed out but the effects arn't there in the real game. I don't know if that's to make it harder or what, but it seems almost like a bug.
Also, to bloundhound, if you want you unlock the extra ships and turrets you have to complete certain goals, something you can't do if you're only building one ship type as some of the goals require you to build x number of a certian kind of ship etc.