You have to access this URL from within the desktop application: https://itch.io/my-collections
From there, you should see options to move/remove the item from a collection.
You can also access this URL from any web browser by logging in and doing it that way.
Sadly the item doesn't show on that URL, or under 'My Collections' on the browser; I only see it in the desktop app, at 'itch://collections/'. I'm pretty sure this is a programming bug where that view is showing an item that's been deleted from itch.io, and I can't find any option to remove it from the collection.
Again this is a really minor thing and doesn't break anything! But it bugs me a little :^) if it doesn't get fixed I suppose I can delete the collection and make a new one without this game.
