After a bunch of mediocre starts (level 40-60) I've finally got the game whupped. One thing for people playing this wondering how players are getting so much money: you get 10% interest between every wave. If you can get 10000 gold, then you're laughing as you can set up a lightning tower up/upgrade a tower every wave.
Neat game - the room with the eye and the floating was creepy... excellent - though it was sort of easy... There should be a click-count or limit of some kind...