Too Difficult

Im no stranger to tower defense games, but this one is just too difficult. I cant figure out how to get past the second or third level. And every time I beat the first level and close the app, it never saves so I have to re-beat it. Frustrating. Two stars because I do like the first level and I like the concept.

Interesting_ish about The Warsaw Uprising: strategy - defense game based in World War II scenery