I agree, it would have been better to have real "extras" in the background. However, I don't think it really ruins the experience too much, you can just pretend that the background characters fade into obscurity or something like that. It could also be considered like an art or a storytelling style. I mean, at least they are dark like a shadow, not blue, green and pink or so like in Clara: Bittersweet Day, for example. Still, it would have been nice to get a response from the developer here.