The ornamental design for a gamemachine, as shown and described.
FIG. 1 is a perspective view of a game machine;
FIG. 2 is a front view thereof;
FIG. 3 is a rear view thereof;
FIG. 4 is a left side view thereof;
FIG. 5 is a right side view thereof; and,
FIG. 6 is a top view thereof.
The broken lines, which define the bounds of the claimed design, form no part thereof. The portions of the design shown in broken lines are for illustrative purpose only and form no part of the claimed design.