Hey Davy, thanks a lot for the kind words! :)
Yeah I totally get what you mean with the art. I'm no artist, but the cutscenes in particular I had to rush to get the game finished in time. :D I already had a plan to work on those over time and improve my skills by practicing with this game. The art I worked on the most would be the character profiles, as you might be able to tell. They're a bit better than the rest of the art. If you want to contribute with 16x16 sprites for the kid characters I'm on board! I love collaborating on a project with other game devs, so I welcome you with open arms.
The art on the cards is AI art, which I'm kind of on the fence about replacing it with my own art or not. On the one hand, I would like the whole game to have my own art in it, but on the other hand, it saves me a lot of time and since they're fictional creatures for a card game within my game, the art style doesn't necessarily have to match the rest of the game.
The rest of the ideas you brought up were already on my TODO list. :) Day/night cycles, other characters to interact with on the playground, etc. I plan on continuing this project for a while, adding more to it until I feel like it's ready for Steam (it would be my first Steam release)!