So, Thomas Jane, the star of the 2004 Punisher movie, made a Punisher fan film.
I only found out about this through a Comics Alliance article.
Like Chris Sims says, it provides a bridge from Frank Castle being a guy who's avenging his family to him being a guy who's going to start wasting crooks on a regular basis.
It reads like one chapter in the hero's journey, so despite the fact that it's a satisfactory and self-contained story, it does feel like something is missing (something besides a full sequel to the 2004 Punisher movie). None the less, it's a fun ten minutes.