Damn the number of ads!!! Every action will lead to ad. There is an option to upgrade by seeing an ad or buy it with money and then see an ad :). You just can not, not see an ad. After few levels the level up stops using ingame currency, then you need to see ads to level up everytime. I guess the devs know that no one will play this game for long.....so extract as much ad money as possible. Which gives a very bad gaming experience. Simply playing this game gives a headache.