Okay, we have our main elements in place and are ready to add the final bit of logic to run the game. But how will everything work?

We will use a system of countdowns to add new meteors and new health packs, as well as a countdown that will incrementally make the game harder to play.

On touch, the player will start the game if the game is not running, and also add bombs and explode them during gameplay. An explosion creates a shockwave.

On update, we will check against collision between our _shockwave sprite (if visible) and all our falling objects. And that's it. Cocos2d-x will take care of all the rest through our created actions and callbacks!

So let's implement our touch events first.