Hello, thank you for your feedback!
We will be updating the UI slightly as we're also upgrading the game to be in 4k.
There already is a textbox too, it is a transparent black overlay, it's more noticeable when you see how it looks without it. (by pressing H to hide the UI) I was going to make it darker, but personally I liked it being more transparent so the background art was more visible.
We are still experimenting with the side images too, we may end up removing them all together if a good looking solution doesn't come up. Hopefully we can also find a better and more obvious look for typing in names, but that was how Ren'Py did it and I'm not entirely sure if there's a way to change it (we'll find out sooner or later)
Thanks for playing!
-Noir