While of course it's simple, it's "enough" in its own way. Though I have a request. Have an upgrade system, such that even though you eventually hit something, there is something you keep with you... money or experience. Then with these, maybe you purchase like, a speed upgrade so the next run doesn't start out as slow. or a double-jump ability, so you can avoid obstacles. Or a more-obstacles upgrade, which, though it makes it harder, boosts your score more. That's to say, while some may say add more "stuff" to it, I'm saying that you Could have it start very simple like this, but become more the more someone keeps playing it.
And yeah the art style works. It feels intentional