Hi, I just finished the game. Your art is amazing, I'm super impressed with what you were able to do in only a month.
I ran into some bugs, but I see they've already been mentioned below.
You have a very cool and unique battle system, but I must admit it took me a while to get used to it. I never found out the slime's other weakness (I only discovered Thunder). Also Mari died a lot while battling, which was very frustrating. In particular the battle with the three monsters (right before the first boss) I had to redo six times before I finally won. (I honestly was about to give up.) It seemed to me that 90% of the time they were targeting Mari. This made it super difficult to get anything done.
That said I had less issue with those boxes, as I quickly realized I needed to use counter.
Some other thing that confused me a lot in the beginning, was the fact that Attack was already targeted, so I didn't need to click on it first and then the target the enemy. I often forgot this in the beginning and ended up attacking the wrong enemy.
For the money minigame, I was surprised when it continued after a third time. I agree it felt too long. I would just do three rounds of it, instead of five.
There's no menu?
You did an amazing job. I'm definitely intrigued and interested in playing a continuation of this.