I have found with several of the games (Moonlander and Racer) that advancing from one part of the project to another sometimes changes package paths for certain files to en.rush.games, which isn't correct. All game projects use com.codegym.games as the start of their package paths, so I am not sure where this en.rush.games is coming from. There is no mention of these changes in the directions, so I don't think it's intentional. In the Moonlander game, this happens to ShapeMatrix.java. In the Racer game, this happens to RoadObject.java with its attempt to import ShapeMatrix.java and GameObject.java from en.rush.games.