The game is free and there are no mandatory purchases. You can fully enjoy the game without making any purchases, but some features will only be available after making a purchase. Creating a good quality game is a very expensive pleasure, and we hope that you realize that the presence of monetization in the game is an absolutely usual and acceptable parameter that allows to maintain and develop the game. We would be glad if you will make some unexpensive in-game purchases from time to time to help us to create new levels.
There are 2 types of purchases in the game: