A game system displaying a three-dimensional game space on a display includes
a
housing held by a player, a tilt sensor provided on the housing, a viewpoint coordinates
determination mechanism for determining viewpoint coordinates in accordance with
an output value of the tilt sensor, and a game image generation processing mechanism
for generating a game image based on the viewpoint coordinates determined by the
viewpoint coordinates determination mechanism. The game system allows the player
to feel as if the three-dimensional game space is tilted in accordance with a tilt
of a game device, etc., with a minimal processing burden.
