You can set the block sprites as a Bullet behavior, and On Start of Layout set their Y speed to a certain number. Or, if you'd rather not do that, enable Physics and World Gravity, so they drop.
What is important however is scoring. On Touch > Object tapped > Destroy object
Add X to Global variable Score (to keep track of score.)
Ah, formatting. The two actions in Object tapped would be destroy object (if you want to them to vanish once tapped) and add a certain amount to a global variable.
You can even have 1 event sheet with the Global variable. Event sheets can be added in (in Event Sheet A, include Event sheet alpha. In Event Sheet B, include Event sheet alpha.) Doing that will reference Event Sheet Alpha in Event Sheets A and B.
Event Sheet Alpha has Global Variable Score.
Event Sheet A has on tap, add X to Global Variable Score.
Event Sheet B has on tap, add X to Global Variable Score.
So you have one Event sheet that keeps track of the score for the entire game. Remember to link them by including Alpha in all of the Event sheets that you want to add to, subtract from or reference the game's score.
PS: A, B, and Alpha are stand ins you can name your Event sheets whatever you want.