So I was working non-stop up until literally the last minute and totally missed that the jam was extended for 24 hours (which I am very grateful for).

In my haste I submitted what I had at the time, but I would love to improve/test it over this extra 24 hours and submit the more polished version. Is that possible? Is it as simple as just submitting another game?

You should be able to edit your submission.

Yes, you can edit and update your submission right up until the deadline :~)

Thank you very much!