Really great job. Some feedback from my first hour - I cleared the third gym leader first try probably somewhat luckily. Now I'm in the fourth zone and massively under levelled, so get stomped by most of the trainers. Means it's very hard to earn any money to improve the deck to start moving towards the next gym.
Suggestion might be to make it so you can return to previous areas to train in case you find yourself in a zone that's too difficult. I see there is a timeline at the bottom so maybe that could be interactable to return to zones.