Golf
A green in the garden at the fly's own scale, a tilt and a few mounds per hole, five holes, fewest strokes wins. The ball rolls down the gradient under scaled gravity and against the grass. The fly reads the green by trying lines either side of the cup in the same physics you see; with its brain on, the connectome chooses among them and learns from where the ball finished.

Five holes
A green in the garden with slopes to read, at your size, five holes against one fly. Fewest strokes wins. It loads the fly once, about 3 MB.
GFly