Hi everyone,
After playing the game again, I came across some design errors.
When the game starts, you have to choose your difficulty. When choosing, if you cancel the difficulty is not initialized. All the variables are at 0 and the switches are off. In short, in this mode you don't gain xp or gold, and you don't heal between fights. I don't think you can go very far in the game like that but it's a good easter egg (a hidden difficulty!) so I think I'll leave it. And if a player does it by mistake, it's easy to change the difficulty back later.
Second mistake, the battlebacks are not in the right resolution, which compress them. But after playing again a bit, it's not especially noticeable. So I won't update the game soon,
Thank you for your support,
David Nguyen.