what to do next

i have a charcter that i modelled but i am not sre how to make game out of him.

make him a simple environment, maybe just a big cube, place a couple of objects inside it, begin to play with logic bricks as the character approaches or touches the objects. just play around while getting to know blender and the ideas will begin to come. the worst thing to do is to stare at a blank piece of paper waiting for something to happen.