Originally Posted by
BlueCanary
Some of the levels are indeed quite maddening, but you can get through all of them without having to buy boosts or paying money. I never bought anything, even the coin boosts and I got to island 10 and a few into island 11 without them. For the ones with a timer, try to clear space if there's boxes and try to make as many special gems as you can, try to smash them into each other if possible too and the score will fly.
I can't really speak for BubbleMania because I haven't played it in months, but I got through all of the levels when it was first released without buying anything other than the long range boost (before it cost gems) either.