Yes, 球球滾進洞-益智遊戲 is free to download, however it contains in-app purchases or subscription offerings.
Not enough reviews to make a reliable assessment. The app needs more user feedback.
球球滾進洞-益智遊戲 has several in-app purchases/subscriptions, the average in-app price is 8.00 H$.
To get estimated revenue of 球球滾進洞-益智遊戲 app and other AppStore insights you can sign up to AppTail Mobile Analytics Platform.