Use arrow keys to move. This is sort of like a micro:bit emulator.
Updates: November 25 – Added scrolling, only to completely break everything, including the camera and player coordinates change 36 times the amount they are supposed to (but this is fixed by dividing by 36). And sometimes (very often) the cat and/or t.o. (test object) do not appear when they are supposed to. If anyone has any idea what is going on here, please tell me. Febuary 24 – Noticed the player is only shown if in the center of the screen or at the edge of the screen, and the t.o. is only visible when it's coordinates are the same as it's position on the screen. I think this will be helpful to me and anyone else trying to identify the problems, but some things still remain unclear. Further investigation will be necessary.