The ornamental design for a gamecontroller, substantially as shown and described.
FIG. 1 is a rear, perspective view of a game controller showing the new design;
FIG. 2 is a front view thereof;
FIG. 3 is a rear view thereof;
FIG. 4 is a right side view thereof;
FIG. 5 is a left side view thereof;
FIG. 6 is a top view thereof; and,
FIG. 7 is a bottom view thereof.
The broken lines illustrate unclaimed portions and form no part of the claimed design. The broken lines, which are adjacent to shade lines form the boundary of the claimed design and forms no part of the claimed design.