Beg to differ, when I think of an ugly game, I think of Crawl.

Its quite a deep question.

A storyless game, even a intentionally designed one, doesn't exist as story is in its definition a set of narratives, and interacting with a setting is a way to force narrative elements. Even static pieces of art have a implied narration. You fill a canvas with the pitch black color and name it "black" you will have people who will discuss it. Don't forget that visuals and music can enhance the story as well, or even tell one on their own.

Even games like Pacman still had peoples minds running wild, because the game stood out in a way, as arcades were primary filled with space-games or other games where you had to shoot stuff (not to mention shooting galleries). The consumer will fill the gaps regardless of the presentation. In fact, minimalism may enhance narration. The reason why classic games had huge instruction manuals existed because the developers and storywriters wanted to give a clear vision of their project to the audience, instead of the audience filling the gaps. Just look at The Legend of Zelda.

Regarding presentation and atmosphere its never about the "what if's" but about the "how's", which is already much deeper subject than you may believe as questining the hows are always widely interpretative. While "what ifs" are mostly binary (if its this, then it isn't that).

You put 10 people in a room and ask them how they feel a certain way when they played Pong, the answer that each and every one of them will give to you will be a unique one.

That you don't put great emphasis in storytelling is just how you prefer approaching video games is the perfect approach for you because it is your unique way on how you see things. In other terms, it is your unique taste and your explaination of the "how" question. Thinking about it further, even feature complete games are nothing but a canvas for your imagination with focus on your tastes.

Go ask yourself the question why your favorite video game stands out compared to other games of similar type and I promise you that you will spend more time thinking about your favorite video game than the ones that can be directly compared. Now think about the previously mentioned black canvas. Some may just see the black canvas, while others may see something deeper. Whether or not that reflects the reality of the artpiece itself is another question.

Besides the reasoning that games without a story don't exist. As long as graphics and progress exist, so will the ever lasting progress in graphical fidelity and style. You could remake Pong but with next-gen graphics, in fact I would love to see a project like that just to see how far you can push graphics with such a simple concept. I wanted to make a Crysis joke but I'm reminded that there actually are PCs now that are able to run the game :<!

No one said it has exclusive right to being ugly.