Thank you very much for the extensive feedback! I really appreciate it! A lot of the issues you brought up I already had in mind to fix in the future (as you said, you only have so much time in this particular bootcamp), but there were a few ideas in there that I can definitely add to the list of improvements, like buying cards from kids. I thought of doing "quests" for them on the playground scene, or maybe trading cards with them, but I didn't think of just straight up buying the cards they have to offer.
Also, the ultimate goal of the game is to pay back the loan shark kid. There's a countdown for when you have to help your mom with the rent. In a way, the losing condition is not being able to help mom with the rent, while the win condition is paying back the loan. I admit, I didn't have enough time to add more information for the player, so I rushed it, but I'll get there eventually. :)
Also, I did the art myself with very little time, so I agree that it's not that great (I'm but a simple programmer). The art on the cards is AI art, so that's why it's leagues better than my own, but it has it's own style and of course strange little quirks and mistakes that AI tends to do. But quirks are ok for fictional creatures in the card game, so I was fine with it. But I wouldn't use AI for the characters. My current plan is to just iterate on the art myself until I get it to an acceptable level.