Slingshot Train

The main gameplay is to launch the train out by dragging the screen and using the bouncing force. You need to collect gold coins to upgrade the bouncing power, otherwise the train can't reach the track and keep moving. But what disappoints me is that from the sixth level onwards, if you don't watch the ads to upgrade your bouncing power and other abilities, you won't have enough coins to continue to the next level. I don't really like this kind of game that requires watching ads.