It's actually on the site...
https://lestrades.com/game/120489/

Sorry for the delay in answering.
So, what you should do when you can't find a game here:
- Go to their Steam page using a browser
- Replace 'store.steampowered' with 'lestrades'. Optionally, you can replace 'steampowered' only, but you'll have to deal with an error message, or you'll need to use http instead of https.
- So, in your case, it would lead you to some page like https://lestrades.com/app/1251210/ (Also works with packages: /sub/123456/ or whatever)
- If the game is on Lestrade's, it'll redirect you to its page. Otherwise, you'll get an error message, along with a prompt to try & create the page automatically. (I'm not 100% sure non-admins can see that button, tho'.)
- In case nothing works, wait for up to 24 hours. Sometimes, the game is too recent.
- Also, some games get renamed by their author, making it harder to find here, and the /app/ link works fine for those.

PS: if a game is in your wishlist on Steam, it'll automatically be added here once the game shows up here and your data is updated. So you can add the game to your wishlist to 'monitor' its addition to LT's.

Oh i didn't know that !

Usually i just use the search feature to find a game, but Dungeon No Dungeon had no result ...

Thanks for the tip :)

Yeah I don't know how to advertise these search features..  there are so many... Like, do you know you can add "+epic" (or other store) to search only inside one store? Or "-steam" to narrow the results to anything not on Steam. Things like that...

No i didn't know that.
I mainly use your site for trades as it was a replacement for Barter and/or Steamtrades. I don't know how many trades are made a day on Lestrade's but i don't trade much nowadays ...

Apart from documentation, having tooltips popup once in a while could be a good idea. The user can always disable it, if she doesn't find them useful.
For the search specifically, an additional icon with an advanced search should be enough.