When in balance mode, Nybble correctly adjusts pitch to remain straight(er) on a tilting surface. My Nybble, however, when the surface tilts left/right (roll), adjusts the leg height the wrong way, i.e., when legs should be longer, they become shorter and vice versa. This way, Nybble rolls off the surface more easily than without balance mode.
The roll adjustment is designed inverted to remain balance while walking/standing on flat surface. You can design two modes by changing the coefficient for rollAdj in adjust() function (in OpenCat.h). You can flip the coefficient by adding a key on the remote.