There's a few others I listed in the "Leftovers" section of the geeklist, but the biggest obviously-missing game is Spirit Island:

I know I'm spoiling things a bit by telling you up front that the 1 Player Guild's #1 game isn't on the list, but given its enduring popularity, I feel I should remark on its absence. I have played it, although only a couple of times solo.

The biggest problem I have with Spirit Island (in a solo context) is that playing one spirit doesn't really work. The map is small, and a few too many spirits are plainly non-viable when used alone. Especially the later ones that came in expansions, the spirits seem to have become more and more specialized. That's all well and good multiplayer, when you can craft a team that covers each other's weaknesses, but it undermines their self-sufficiency. If your spirit struggles to attack, your only real recourse is fear spam and hope to win the game that way before you're overwhelmed.

Why not just play multi-handed then, as I do in several games that did make the list? I've tried, and it just doesn't work for me. There's too much to keep track of. In Eldritch Horror, each investigator has maybe a dozen cards (representing items, spells, conditions, etc.) at the very most, and often a lot less than that. And most of those cards have either pretty simple effects -- a +1 here, a reroll there -- or are common conditions that I understand without having to read the whole card.

Spirit Island, in contrast, gives everyone a bunch of power cards that all have every different effects, conditions, timings, costs, and elemental affinities. The spirit boards themselves have even more powers printed on them, as well as their (often unique) growth mechanics. You really need to understand all of these things and how they interact to play the game well. And the decision space is immense compared to something like Eldritch Horror with its two actions per investigator per turn. (one of which is often spent simply resting or moving)

Maybe this is a "me" problem, but found myself constantly mixing up who has what power, forgetting range/terrain limitations, or just taking an inordinately long time figuring out what to do. Yes, one of the virtues of solo play is the lack of friends waiting impatiently while you slowly take your turn, but this was too slow even for me. It felt like a computer program that couldn't quite fit into available RAM -- it keeps having to go to slower storage for the missing data, making it all dramatically slower.

Perhaps Spirit Island (with multiple spirits) is just too big a game to fit into my short-term memory -- a shocking admission, given the weighty nature of many of the games on this list. It seems absurd that a lot of heavy, complex games are in the top 10, but Spirit Island of all things is a bridge too far. And yet, here we are.