grazie, troppo gentile
using the qwerty12's suggestion to use the 'hildon' call for the sound was pretty easy to add the sound feedback (and seem pretty light on the system). Yes, playing with the leds is pretty addictive and I always feel that the feedbacks are never enough; I just need to find a smarter way to make the led loop (the function carnevale()) because now freeze the application and that is pretty annoying, maybe acceptable but still annoying.
I admit I really didnt spent too much time on the help graphic but was just to show how easy could be to integrate more extra info on the interface, pygame support the trasparent png (slow but still acceptable) so it was enough to just 'draw' the extra layer before the 'flip'. Thank you for the screenshot, I had some doubt about the height (I usually use a 60px top bar and probably some themes use a smaller size). I guess I can just add some extra graphics on the bottom to avoid the ugly repeating effect. I think the application is still enough 'reactive' but it seem a bit too heavy on the memory, I suppose is time to return to the simpliciest version to have something usable when the tablet is not charigng laying in the bedroom