on the homepage it says: "If you do not wish to register a website/forum account, you can also get the game through the Humble Widget, on the Humble Store or on itch.io"
I bought it here on itch.io but the first thing it wants from me when starting is that i login somewhere, not even mentioning where.
I paid over 20% extra for not having to create yet another account!
btw. the download is only the installer for the installer? it seems when using the itch.io app