No tutorial, no instructions ingame, just a white circle that randomly appears and says "tap", but gives no clue what to tap or what the objective is. It won't hurt you to give new players a bit of guidance in HOW TO PLAY YOUR GAME, devs. This confused player gave up after five tries and fails; I'll take my money and time to better-designed games.
The interface was no help, either. Nothing clearly labeled, just icons that had no hint of what they were for. Random tapping on those icons found no instructions or help menu, either. Fail, devs.