2X - multiplies the level score two times
Clock - slows down the timer for given level
Heart - gives you an extra life
Coin - adds 5 coins to your coin balance
There are over 30 shapes total in the game and plenty more to come. The more you play the more basic shapes you unlock. To unlock bonus shapes you need some coins. Collect coins during the gameplay or get coins for watching video ads in Gallery. While basic shapes do not bring any advantages, bonus shapes can multiple your level score many times or supply a few coins when successfully adjusted.