The BananaBread demo ran very smoothly at fullscreen, 1920x1200, on Firefox 19. I was very impressed. I'm running on old hardware: a 3GHz Core2 Duo and NVidia Quadro 1700. I know it's not a full game, but it's awesome anyway.
It runs OK without asm.js, but it's liquid smooth with it.
What else do you need?
They probably couldn't have done more even if they wanted to, though, since asm.js or not, browsers can see only use the OpenGL ES 2.0-based WebGL API's. That's why I'm hoping the OpenGL ES 3.0-based (or better) WebGL will arrive very soon, although I haven't even heard if the Khronos group is working on it, so it's possibly they haven't even started yet.
The art assets of the Citadel demo are I believe the same as in the Flash demo, which were optimized for a more mobile-friendly and touch-friendly environment.
However we also showed a full Unreal Tournament demo running, as I mentioned in another comment, both at our GDC presentation and in the booth where people could play it. That's a full desktop level.