I sent the game link to few friends and they are all addicted (and they squat the top 5 . Seeing their score I assume that there are strategies that produce efficient defense against dragons and that's what maintain the game interrest to me.More evenly distributed waves of dragon would make that a game would last much longer and could become boring.I still regret the lack of a 'reset' button to avoid starting the game many times before getting what I think is a good beginning.