I'd say marketing was the biggest issue for the game's numbers because I didn't even know the game had been in development for 3 years. I thought it was like a handful of months at development.
I had to think about what the game was lacking because you had a decent list a few months back that covered everything I can think of, but I did get to one I think wasn't listed.
Presentation.
Not in the events, but just in the battles and choosing the destination. For battles I just think a handful of different locations for the fight to take place because all I remembered and like one other location from the lake event, and this might be a case of not playing for some time, every fight was in like the same background. Which made them all blur together in my head, so maybe like 3 or 4 instead of one unless this is an extreme case of me forgetting in which case ignore me I'm being stupid. The battle location is nice, but once you've seen only that same art after a few runs, it gets a little old.
But the map, or next location, certainly didn't do it any favors. It's the definition of "Functional but unremarkable." That is again not saying the art for the background is bad If I had to think of other card games I've played, the big thing I think about it the large if simple maps I could plan to go down. While the cards are more details, there's not a lot of choice it since you only know what's up ahead by 2 so you're far more reliant on RNG than on others, while also at times feeling a bit more railed in on choice.
Take all this with a grain of salt, I've never made a game only seen them made. I am under no illusion it is a painless affair or something that could be accomplished overnight. I do hope this is only a road bump in you're journey and not the end of the road, but all I can do is wish you luck.