I agree that getting money (it's called hemopoints in the game) is harder than winning, the fights are lacking extra features that would make it more interesting, but I will for sure add more things to it like items which can be used at any time in the fight (you can already see 3 grids for them in the fight and you will be able to either buy them in the shop or get from ?s).
I'm also planning on adding Taints: the passive effects that have negative and positive effects during the fights. You will be able to get rid of them at Witch's glade.
Note that the better the card is, the more hemopoints you will get. You can see all info on Google Sheets. Increasing gold bonus for faster clears doesn't seem like a good idea, but I may do something like the more you kill the more you get.
The mouse was intended to be an easy enemy, mostly for the first forest, but there will be harder enemies in other forests later in the game
I will also add different playable characters with different starting decks, so there will be different strategies to play with some of them
Anyways thanks for the feedback <3