A joystick device comprising: a hollow housing formed by an endless boundary structure and a ceiling structure having an opening; a control-stick having a head portion and a stem portion, the hollow housing surrounding the stem portion of the control-stick such that the control-stick extends through the opening in the ceiling structure of the hollow housing with the head portion of the control-stick outside the hollow housing; and a plurality of biasing curved arm members extending outwardly from the stem portion of the control-stick in a manner so as to be movable with the control-stick relative to the hollow housing along a plane at least substantially perpendicular to the stem portion, wherein each of the plurality of biasing curved arm members extends from the stem portion along the plane and has a curved segment with a convex side of the curved segment directed towards a respective corresponding portion of the endless boundary structure of the hollow housing so as to bias the stem portion of the control-stick away from the respective corresponding portion of the endless boundary structure of the hollow housing when the control-stick is being moved towards the respective corresponding portion of the endless boundary structure, wherein the plurality of biasing curved arm members are movable with the control-stick as a whole relative to the hollow housing along the plane, and wherein the plurality of biasing curved arm members are distributed along a circumference of the stem portion of the control-stick in a manner so as to cooperate with each other to centre the control-stick with respect to the opening of the ceiling of the hollow housing. a hollow housing formed by an endless boundary structure and a ceiling structure having an opening; a control-stick having a head portion and a stem portion, the hollow housing surrounding the stem portion of the control-stick such that the control-stick extends through the opening in the ceiling structure of the hollow housing with the head portion of the control-stick outside the hollow housing; and a plurality of biasing curved arm members extending outwardly from the stem portion of the control-stick in a manner so as to be movable with the control-stick relative to the hollow housing along a plane at least substantially perpendicular to the stem portion, wherein each of the plurality of biasing curved arm members extends from the stem portion along the plane and has a curved segment with a convex side of the curved segment directed towards a respective corresponding portion of the endless boundary structure of the hollow housing so as to bias the stem portion of the control-stick away from the respective corresponding portion of the endless boundary structure of the hollow housing when the control-stick is being moved towards the respective corresponding portion of the endless boundary structure, wherein the plurality of biasing curved arm members are movable with the control-stick as a whole relative to the hollow housing along the plane, and wherein the plurality of biasing curved arm members are distributed along a circumference of the stem portion of the control-stick in a manner so as to cooperate with each other to centre the control-stick with respect to the opening of the ceiling of the hollow housing. <EOS>