In total, I have not enjoyed this trilogy of Lupin III OVA. I do not care for this animation style or the choice of voice actors they've gone with for the English dub. I acknowledge that it is smooth animation, the character design and art style are just not for me. It just doesn't have the focus has shifted from being lighthearted comedic adventures to a more dark and serious tone. This one is my favorite of the trilogy. This is the only one that has both Goemon nor Inspector Zenigata in it.
I will give credit that each of these specials have introduced interesting henchmen that our "heroes" have had to fight. This one, as the title would imply, is an adversary for Goemon.
Even upon the completion of the OVA the story feels incomplete. Filling in the gaps is where the series comes in.
The story is pretty straight forward. An evil Jaws type henchman is released to assassinate some people, and Goemon feels honor bound to fight against him. The plot points write themselves. Sadly, these plot points aren't handled very well. There needs to be a moment where Goemon feels truly defeated and at his lowest point. This happens, but it feels pretty weak. Likewise, there should be some sort of training montage where Goemon overcomes the mental obstacle and is ready to come back triumphant. And his training was not handled very well either.
And to not get into spoilers, but the payoff isn't all that satisfactory either. It just sort of ends.