The way I try to look at GUI design is that if the user has to think what to do next (e.g. "what button to press") or is unsure wht to do next (e.g. "I pressed button but screen is blank") then something is "wrong".

Although the screen is hires the buttons are quite large - mainly by design the GUI has to be simple to be usable.

The best thing to do is to get feedback from other users or while you are designing your app do a quick mock-up (e.g. screenshots or via qt designer). Maybe post stuff online.

I think boobie-shaped buttons would look great.. You can animate them and make them jiggle.

Like:
"..The sound of one hand clapping.." or
"..If a bear farts in a forest does it make a sound or smell although nobody is there to hear & see it?".