Trying to make a Stack-like game but end up making sandwich

I was thinking of a game simple enough that I could develop with Unity engine within a couple of months. Then I found a classic game "Stack" on Google Play. Trying to make a game that works only with screen tapping like Stack. And finally I made a Sandwich making game. 

Players are supposed to tap on screen while the moving sliced breads hovering back and forth to match them. Just like the stacking of tower in the game Stack.