Last level is easy. Use the Pirate and steal his resources every chance you get. Use defend until you can get full army of elephants, archers and healers. I beat it first try! :)
Getting achievements should actually give you something. While the extra furniture is cool to look at, I wish you'd get some sort of upgrade for completing an achievement. 5/5!
Ohhhes noooes. Sorry to hear that. How do other Unity based games work for you I wonder?