Go here: https://www.epicgames.com/store/en-US/p/itch-io

Under external links Click browse games then get a 404 because it sent you to https://itch.io/game instead of https://itch.io/games.

So clearly if you could add an s to that URL you should but I think this brings up an interesting point.

I would redirect 404 to https://itch.io/. (or have it include some games for sale) Why?

1) It's what a few stores do and as a user it makes sense because I am going to the link because I want to see games on a store page. A 404 without any games for sale is a missed shot for all developers.

2) there ain't nothing to do on the 404. The 404 error page could be improved in general but I'd love to see people looking for games, find games. Even a small featured game on the 404 pages would be interesting. Maybe like some web embed game that the staff picks or so?

3) lastly, this is a big one you don't even need to remove the 404 page, just modify it to also have elements from the home page. Keeping in mind the user might not be logged in, display games that you think are relevant to the user. Exposing "On Sale Picks" or "Latest Featured Games" might just be enough on the 404 page to keep people browsing.

Either way, hopefully, the link gets resolved.