Yeah I will agree the text was a bit hard to read, especially the intro in white.
I enjoyed the audio and the setting, but I didn't really get the sense of it being underground.
I don't usually play card games, but I guess you really need variety as well as a way to view and customize your deck for it to really work, as well as a way to save to your hand or some other mechanic that makes it more tactical and less random. I guess I'm stating the obvious, there is always the issue of time.
Sailing around on mini adventures to find new cards is a really nice idea and gives great opportunity for worldbuilding. (Y)