Day 91 here...took a while to get the hang of it, but once you pass level 20-something, it gets easier. Btw, the little girl inside the castle throws grenades every once in a while...
The hard badge was pretty tough. Only got it thanks to OmGgITzMoses' strategy. After you get the 8 fighters and drone repair to 400, laser turrets are the way to go. If you don't have the turrets maxed out, there is NO way to survive the onslaught of the small fighters near the end.
Game isn't buggy at all. Saved all my games, worked fine every time. Made it to victory in ~2hrs. Not a single animal had to be revived. Is there a badge for that?? :P