Yep, this game is a lot of fun. Anyway, the default license for An Untitled Story is pretty clear:
Any game made by editing this source file or using any audio or
graphical assets contained in this source file must be released as freeware
and credit must be given to the original author (Matt Thorson).
It must be made clear that the released game is not the original,
official version released by the original author.
So I'll have to add an info screen, but it seems that a source port shouldn't be a problem.