Please add support for Virtual Buttons, it can be useful when running the HTML5 game on mobile, for eg:
We can click A and accelerate on PC but not on Mobile, we have to rely entirely on the Mobile TouchScreen, which is not helpful for situations where the Touch / Mouse has other functions.
And also for the Screen Rotation of Mobiles, if possible …
How about adding game object to the screen that if clicked will do exactly what it supposed to do? Going with buttons as images (sprite objects) has also this advantage that those can be much more that picture of say, ctrl key. If ctrl key is responsible for jump, you can display little spring here, for reload button, you can display image of clip (perhaps even clicking ammo counter could reload?), etc.