The apple moves on it's own at a rate of 0.1 steps per second, give or take. Hold SPACE to supercharge it and make the apple move at [velocity] steps per second, which increases higher the longer you hold SPACE. When you let go of SPACE, the apple will return to it's usual step rate and velocity will rapidly decease. It's no technological miracle but as my first project in five odd years I think it's fine.
I credit... no one. I actually came up with this on my own. It feels oddly good to code again.