Hi Surli! You really want to make games? Your YYP file is not sufficient enough for us to discover your game, it is just a project file for the game settings in the GameMaker editor, there are no contents along with. Where are the sprites, sounds, musics, and other stuff?
You have made a lite modification of the original Space Rocks shooter by Friendly Cosmonaut. Good getting started. You know, I have modified and colored sprites (and gml code!) for the same project, ready to be shared. If you are interested, I shall send you the sample. Glad to help you, as a welcome to the amazing world of game creation!