Most weapons have attacks mapped to the X and A buttons and some sort
of special move attached to the R button, which can be another attack that can be used with the other buttons to generate simple combos or something completely different entirely.
If you use one
of Jin's
special moves a giant robot hand with come out from the side
of the screen «
attached» to the robot, but the hand pops in where the full screen option would have it pop in.