[Game] Money Leveler

I have created a android game named Money Leveler

play.google.com/store/apps/details?id=com.duphoff.moneyleveler.android

Money Leveler is a logicical game where you try to get as much money as you can to reach the top of the leaderboard. To reach that goal, you try to combine at least 3 coins (or notes) of the same value. If you have combined them they you get a higher grade coin, which you can also combine to higher coins. If the field is full of money, and you can't put any coins into the gamefield anymore, you get all the money on the field on your play bank account. With that money you can buy upgrades (for example a bigger field). You can also maximate your win by leveling up or get achievements.

Here are some pictures:

I would like to hear some opinions