This is a really simple game to start out. Up arrow - Jump Left arrow - run left Right arrow - run right You can Jump in midair by running off of a platform and simply pressing jump while falling. Also, if you see some BLUE orbs, try hitting them! Something useful will happen! If you die, press the green flag to restart. Touching anything red will kill you, and you can touch a ladder to climb up it.
I used the Usborne 66 Jump starter pack to code a simple platformer game, so that was useful. Also I added a few sprites to my library, so you may see them again in future. Sorry if it isn't great - I'm a beginner, even at a programming language this simple.