All you have to do is select a pencil or an eraser from the bottom left corner and draw with the arrow keys. The red dot is the pen and if you want you can drag it to your desired drawing place. When you have finished press the test and a block will come out for you to play around with. You can change the size of your pencil (or eraser) with the pencil size variable.
Thank you to @griffpatch_tutor for helping me out with the platformer code. If there is anything that you think I should fix or change please comment. This is my first project so don't post any rude or mean comments please. Changelog: 2nd of Feb added the pencil size variable. 10th of May reshared the project added my new intro to the start. 11 of May edited intro fireworks. 13 of May edited intro costumes