A simple way to do this is the player transform.
Get player rotation or transform and do rotation +-180 degrees.
Torque script step in radians, you can have a value between 0 and 2PI.
Conversion help: (equivalence decimal)
0 radians = -2PI radians.
PI radians = -3PI/2 radians.
example: (z 180 degree rotation)
%objTransform = %object.getTransform();
%tryRotation = "0 0 0 0 0 1 " @ mDegToRad(180);
%newTransform = matrixMultiply(%objTransform, %tryRotation);
%object.setTransform(%newTransform);