Very addictive! I have to struggle with spending on this app. The levels become so difficult, I've spent 5,000 coins just to complete a single game. Its frustrating because the level can't be beat even after the maximum power-ups have been used in the start-up which causes you to spend a increasing amount of coins for every five additional plays. I get really angry because it feels like a money grab from the game inventors. It makes me stop playing.