This is a platformer engine. I've created my own, because I wanted to test a new sort of platformer scripts. Instead of using a big forever loop (like most of the platformers on Scratch), I've used multiple scripts, starting with when key pressed hats. it keeps smooth by using repeat until loops. Only one forever loop is used, the one that changes x and y by variables. This kind of platformer engine will be a little less responsive for smaller projects, but when youre project gets big, the movement will keep pretty smooth. a forever loop causes a vibrating effect when you don't move. That is fixed here, because it stops calculating when the right position is found. Arrow keys to move and jump Space to change ground