Thanks for playing!
What FPS were you getting, and what kind of hardware are you running on? I know I've been getting about 40-60 on my old laptop with a 1050, while my main desktop (3060) runs at ~165 (vsync), so I'm aware that it runs pretty badly on the older hardware. I'll probably have to add some graphics settings in future.
About the feedback, there's animations, sounds, screenshake and some VFX, so I don't really know what else to change here. I suppose the tutorial's probably still very lacking in teaching you what each of those should feel like, but at the same time I don't really want to go into the handholdy "Dodge 3 times: 0/3" kind of thing (even if that is what the tutorial is doing underneath).
By X, do you mean the controller buttons? I haven't really tested out the dialogue system with controllers all that much, but it seems like this is yet another UI focus bug. It should work fine if you use the mouse to click on the box, though.