I am primarily a digital game designer so I do not feel qualified to comment on the production of a physical game. However, I do think you have a disconnect between your theme about acid rain and your planned gameplay. The focus seems to be centered around a card battle system with the players fighting against monsters. I'm not seeing how your research on acid rain fits in at the moment. I recommend expanding on this aspect of your game. That said, you have an unique art style which works will with the narrative you have described. I look forward to seeing the different monster and character designs.