Firstly, play the game (obviously), and choose the difficulty. Once you select, all you need to do is to get an apple and finish it. Use WASD or arrows to move. There is a checkpoint. In case you die, you'll spawn where your checkpoint is. If you want to respawn immediately, press the 'W' or space in your keyboard. Make sure you need to stomp the red 'goombas'. The more levels you play, the more harder it was. On the level editor, press any of the numbers to choose which type you want. Click anywhere to build. Clicking on source code is recommended. So that the costume size may fit accurately. Prepare the lag before you do so.