I don't mean directly that the inventory looks bad ;) It has a few technical design flaws.
If you let the player adjust the font size, you have to limit that. But then the UI must be able to scale in size if the player takes the maximum font size. This doesn't necessarily make it any easier from a design point of view, instead of directly specifying a balanced design with a comfortable size. As a rule, games use different font sizes for dialogues, tooltips, inventory and buttons, for example. It's better to limit yourself to maybe 3,4 sizes.
Music:
I would prefer the music to continue in the background or start from the beginning. Whereby the music adapts to the location/situation of the game. If the developer wants it to. (more work, of course, but also more variety)
Combat system, nice :) I'm curious!