The default button scheme is... (for me and all my games at least)
Tap Play (touch dont press)- Down
Tap Rewind- Left
Tap Forward- Right
Tap Menu-Up
"Between" menu and Forward- A button
"Between" menu and Rewind- B button
Select- A button
Press Forward- B button and right (great for games where sprint is B, like mario)
Press Rewind- B button and Left
I think the above too aply similarly to play and menu... not sure though
It's actually a lot easier than it reads!