I Got the second highest score while watching Youtube and occasionally glancing at the screen to click. I won't sugarcoat how incredibly boring and easy this game is. If an immortal being had the patience, they could literally play this indefinitely with no issues. I would rather play Assassins Creed trailing missions all day. I actually got every single medal in my 1st run.
Now for the actual issues, the clicking doesn't always register and it is delayed slightly. And when your character is limited to 3 columns of movement, it's wise to make sure 2 falling objects can't fill all 3 columns.