【how to play】 Advance the game while flicking the drills on the screen. While raising the drill power (numbers), get a lot of money and aim for a high score!
【rule】 ・ Drill power (number) will be raised if the drill is placed on the same number drill. ・ The drill can take money and the score is added. ・ Drills can break rocks. The rock hardness (number) can be broken below the drill power (number).