I haven't done too much with the game in awhile since I'm hoping to either find or hobble together a ruleset for larger battles, but I did glance at the campaign cards. Some quick thoughts.
It looks like you took some inspiration from the Zombicide cards with the EKG rhythm strip at the top of the card. I'd actually get rid of that, and maybe make the life circles darker and/or add a large number to the inside to make it easier to see how much life a character has. The starting life circle is very hard to see, at least for me. A darker shade of green might be a good idea.
The medals are a nice idea. I've toyed with the idea of a campaign system that awards characters based on achievements rather than simply finishing a mission. You might take some ideas from the character challenges for the medal requirements.
I understand there is no character progression around stats.
It looks like Miah built that in with his life upgrades. On the John MacNeal card, if you upgrade his life from the start (green) circle, some of his stats increase.
Tannhauser month aside, what do you two think of an unofficial publication with fan-submissions to keep the game / world going? Do you think there is enough fan interest for that, or do we just have to accept that the Tannhauser community will leave for greener pastures after the Frankenstahl is released?