I think you need to reconsider your button layout. A game like Super Mario Brothers isn't going to work well on that thing. Either kill the turbo buttons and not make it diagonal, or modify it in the following manner so games that require keeping B pressed to do something such as run while using A for action commands, are actually playable.
Your current layout is almost as flawed as having A and B backwards, like your prior handheld was. The state its in now, I'll be skipping over it and I think you'll find people become pretty discontented with it once they buy one and realize the button layout doesn't make sense for many games.