Everything is too expensive. Most level are impossible to beat without coins. And the funny thing is, the level that always got me stuck are not even the super hard level. Especially when i got the twice reward. I will stuck on the same level until the time is up. And right after that, i suddenly succeed. It's a bit obvious, don't you think? One of the most greedy app i ever found here. That's why i had to change my 5 stars to 1.