My girlfriend (not a gamer) is addicted to Word Soup.
I (also not much of a gamer) am enjoying browsing through the many Community Games, admiring their tremendous variety, creativity, and (at least in some cases :-) polish.
But here's the thing: too many of these games don't respond when I press buttons on my controller!
Or rather, they do respond, but not to the particular button I was pressing. Sometimes I press A to begin, but the game was expecting Start. Or I try to navigate menus using the left thumbstick, but the game is listening to the d-pad.
I think the problem is that developers are looking at each screen in their game and thinking "what button should I use to control this?" That question only gives the right answer if the player has the same brain wiring and expectations as the developer. A better approach is to ask yourself "for every possible button the player might try to press, what would they expect it to do?"
In particular there are three rules it rarely makes sense to break: