Unpopular opinion time: I disagree with the notion that a game has to be fun to be good. I also disagree that a game has to be fun to be enjoyable. In order for others to better understand my viewpoint, I will now ramble like an insane person:

I would argue that the word "game" is an oversimplification of what a video "game" actually is. The word "game" implies competitiveness or fun, which is why I think you hold this opinion. The reality, however, is that the strength of the medium isn't in its fun, but in its interactivity in general.

Why is it that CS:GO and The Last of Us are both considered "games?" Can anyone even argue that CS:GO has artistic value? Like, at all?

CS:GO is truly, pure and simple, a game. It is a sport and nothing else.

The Last of Us is... what exactly? A narrative-driven... interactive... thing? It wasn't designed to be fun, as that would have contradicted the mood of the rest of the package. It also can't be interacted with in a competitive capacity (barring MP, of course), which means that it isn't a sport. If TLoU isn't a sport, then why is it in the same medium as CS:GO? Nobody would argue that Breaking Bad is comparable to televised football.

So right now we have "art things" and sports in the same medium. What happens when you consider Minecraft? That game has no narrative and really no purpose other than "do whatever you want with it." Does that make Minecraft... a toy? Are Minecraft and all of its clones just interactive versions of Lego?

At this point, we have "art things," sports, and toys(?) in the same category. It's quite a clusterfuck, and I believe this is directly responsible for the extremely limiting expectation that all games should be "fun."

What if the goal of a "game" isn't to be fun, but just to be engaging? Maybe its story is dark, gritty, and grounded in reality. At this point, the fun factor no longer matters. In fact, fun would be detrimental to this hypothetical "game." The only thing that matters here is whether or not the way in which the player interacts with the "game" supports the overall message or mood of the package as a whole. This is why "Mario is more fun" doesn't make it any better of a game, and it's also why story isn't always secondary to gameplay.

This is getting really fucking vague and I'm running on 3 hours of sleep, so hopefully I made some sense here. This post also turned out way, way longer than I had anticipated. Maybe I'll edit when I'm lucid.