- Find an item that you'd like to download (for example: https://archive.org/details/SuperNintendoUSACollectionByGhostware)
- Grab its "identifier" (you can see it in the HTML of the page, but otherwise just use the last part of the URL for a "details" page)
At this point, you could just download the files by clicking on them on the HTML page, but that's slow and concurrent-download-limited... Sooo...