itch.io

Well, from my impressions, the projects "announced" here, are most often made by developers for developers to get a vehicle for promotion. The pitch is not for people to find games, but for devs to promote games. (Your's is a better approach).

I found the discussion I mentioned, it might be of interest to you /t/4748289/itchio-api-for-game-metadata and  /t/5258962/games-recommendation-system-dev-progress

Steam tags are interesting, because they do have a ranking. With enough popularity, they should become more accurate. Then again, if one curator runs in the wrong direction in the beginning, a lot of people might just agree and not question the wrong classification. This is also bound to be influenced by trends over the years. Glaring examples:  https://thejaspel.itch.io/backpack-hero  on Steam the game has no indie tag. Or the fact that peopl voted "rpg" the 15th most important tag for https://store.steampowered.com/app/646570/Slay_the_Spire/ . That game is not even close to a rpg, but opinions obviously differ here.

What it should do is surface DD1 to the player who logs “dread, strategic, investment” and DD2 to the player who logs “fast, replayable, casual runs” and let the player decide.

The thing is, dd2 is not replayable and not fast and not casual either. A run will last like 3 hours. And you do not replay it, you grind it. And that grinding means, it is not casual. Replayable means, you get worth out of a new replay. Maybe you associate this with rogue-lite, because neither dd1 nor dd2 is tagged with "replay value". Or you just used things you think are opposite of investment.

I see here that tag usage changed over the years. Even on Steam with their limited tag pool. What's with turn based tactics not even appearing in dd1? New tag? And what's with all the rpg tags. Those games ain't rpg. And there is no perma death in dd2, hence it not being a roguelike anymore. And notice how it is no longer tagged indie. An interesting signal is the appearnce of story rich and hand-drawn. dd1 was hand-drawn too. 

And I notice that some tags are more accurate than others. Lovecraftian for example seems to be rather accurate. And rpg seems to be noise selected by people that do not know that  just because you control "a character" does not make a game an rpg.

So what does this actually say? Tags are not reliable. Because people have different opinions when to apply them and how important they are. That goes for selecting the tags, and for creating any signal from tags to match to a player.

What I initially meant with the 30 years, there has been reasearch done. Companies use classifications and player profiles and obviously techniques to match those two. Which means two things: 1, you might dig up knowledge how to do this. The theory behind it, and ways that will not work or are established industry standard. And 2, re-inventing this from scratch in any way that can compete with existing solutions is gonna be hard. 

Yeah, having a mapping of feelings a game will invoke and searching for those is well on paper. But this sounds like a thing that cannot be gathered automatically from existing data.