99 Nails

You own a nail gun, and a pachinko machine.  How long can you last?

Each round has 15 seconds of deploying nails on the board, and then watching the balls tumble down into the different holes for points.  If the balls reach the bottom, they either expire, or refund extra balls.  

After each round, enter the shop to spend the cash you earned so far on keeping your ball count in check, getting nails for your nail gun, and upgrading the strength of the nails so they can take more hits before falling out.  

See how far you can go without losing all your balls before the timer runs out!