"Why don't you use the up arrow and the space bar?" cuz those suck, 1. Causes WASD controls to become awkward to use 2. Up and down inputs are easily possible (crouching, climbing, etc.) 3. Allows for easy expansion (for example, I could add J / C for a third button) 4. Mapping controls becomes easier (both vanilla Scratch set-up and Scratch Browser Extensions) While this style isn't commonly used on Scratch, it becomes easier to use once you get used to it. Plus, my games aren't those stupid generic "platformers." My games need extra inputs to prevent the game from being held back.