I'm on level 9531 now and I think that I have stop playing. You can imagine how much I have spent getting to that level. Have observed that sometimes the developer decide on which games you should win. You are also giving very difficult games as soon as they see that you buy booster so that they take away all the boosters you bought with money. Sometimes games you couldn't play with all the can easily be played without a single booster later like I said,on level 9531 so I know what I'm talking a