Shiny: Blender Multitexture Materials

6.  Load image to be used as reflective map

You can use any image as a reflective map.  For best results, try to match the colors of the reflective map to the game surroundings

Reflective maps can't be one solid color.  The brightness of the colors and the contrast between the colors determines how shiny it is.

Model Selected
Edit Mode
All vertices selected.

UV/Image Editor menu >> Image >> Open

7.  Set Realtime Texture Mapping to Reflection

UV/Image Editor >> Image >> Realtime Texture Mapping

8.  Press P to Play

User Preference menu >> Game >> Start Game
P key