Use the right and left arrow keys to turn and use the up and down keys to move forward and backward.
This is a copy of my 3D Raycaster test, except with significantly better pen quality. However, it is extremely laggy on Scratch, which is why you should play it here: https://turbowarp.org/710613833?hqpen&stuck Original Raycaster (less laggy): https://scratch.mit.edu/projects/710567987