Hi,
I've just launched the game, and I have a few important issues:

First, some UI elements seem to don't show up at all: e.g. save slots, key bindings and resolutions in the settings.

Secondly, using a mouse and a keyboard, I can't seem to look at anything else than the ceiling or the floor, and the view spins weirdly, so the game is basically unplayable. I've unchecked “mouse smoothing” and checked “Ignore other input devices”, didn't change anything. I'm yet to try another input method.

The second issue is due to using Wayland rather than X11: I guess he game tries to grab the mouse, which doesn't work with Wayland. Switching back to X11 solves the issue, but it doesn't help with the first one, which also affects reading notes.

Can't really say but you have installed libsdl2-2.0-0 right?

UI elements are fixed now (there have been a few patches since my post, this is probably due to one of them). Regarding the the mouse thing, I'm not sure it's resolved, but since I've temporarily switched back to X11, I don't have this issue anymore.