The game says "A/D or left/right" but only one works at a time. Why not make both work by default? I'd suggest adding an extra hotkey choice, even if it's just for the movement.
Also, it feels like the controls are meant to be one-handed (for understandable reasons) but the default setup makes combat very unnatural. Plus, unless I'm missing something, I have to use the mouse anyway to click on menu items. The ability to navigate menus and select choices with keyboard would be incredibly useful.
Finally, I'd like to repeat another suggestion and say that difficulty options (maybe even simply an infinite health or stamina mode) would make the game much more enjoyable and accessible to more people.
Overall, the concept is really interesting, and I'd love to see this be successful.