For some reason, I cannot get this to run more than a snail's pace. Unity sometimes just does not play nice with my laptop, and I have no idea why. I confirmed Witness is running on the decidated GPU and not the integrated one. I don't know why this happens, but I guess I just can't play this. :(
That's probably it, then. Especially if it's rendering anything at a decent distance. More complex Unity games with long draw distances tend to be the hardest for my machine to deal with. It took a ton of tinkering to get (for example) Edge of Eternity to run decently for me because the scenery in the world is so far off to create a sense of scale. I can see pretty far into the distance in Witness, so that might be the culprit. I'd suck it up at like 15-20 FPS since I really want to play it, but can't even squeak more than about 3 FPS out of it.