Yes, setting the page to an HTML type project allows the thing to run as a page embed. That’s as if the upload has a functional index.html. Downloads can be made available from the same page.
I’m pretty sure the reverse doesn’t work out; as in, a project won’t run as an HTML game, tutorial, sample, or whatever you want running in the embed area when it’s overall classified as a download.
In my opinion, it’s better to offer both the web project plus downloads. That allows a wider range of people to look at the thing.