The ornamental design for a gamespinner, as shown and described.
FIG. 1 is a perspective view of a game spinner showing my new design;
FIG. 2 is an enlarged top plan view thereof, the bottom being plain and
unornamented, the broken line showing of the letters is for illustrative
purposes only, and forms no part of the claimed design;
FIG. 3 is an enlarged side elevational view thereof; and,
FIG. 4 is an enlarged end elevational view thereof.