It's not the problem that it is difficould, but its nearly impossible. Like me beeing stuck on stage 8. When the falgship arrives it comes with another 3 aircraft carriers and 3 battleships or something... and dont forget about the still incoming "small" ships and submarines...and of course like 3 or 4 bombers... I cant find any way to beat that... its not hating, its just unbalanced.
but still a good game ;) I would like to play it till the end but for me its not possible