The best SpeedIFs are usually examples of mad genius; solid, appropriate, non-boring design is rare. The Twelve Heads of John the Baptist, by contrast, is a straightforward process-of-elimination puzzle, like 69,105 Keys writ small. It's notable, however, for meshing a sensible puzzle mechanic with entertaining content in a way that doesn't feel forced; and it has a good feel for one of the key pleasures of IF: the joy of a rich inventory listing, packed full of interesting and picturesque objects.
So, nothing extraordinary here, but a good eye for combining strong, established design elements; and enjoyable to play, however briefly.