The Global Defense Network is always looking out for the welfare of our
planet. To that end, they are always searching for new, talented individuals
with fast reflexes to man their defensive weapons against external threats.
Whether it’s alien attack, a meteorite on a dangerous course or sending probes
down an unexplored tunnel, the GDF is the first line of defense against such
threats. In order to facilitate their search for people, the GDF mainframe is
open to the public. Any new user can log in and ‘play’ the training
simulations, which combine target practice with rhythmic music and 3D effects.
Those with a high enough score will be invited to the real thing, ready to
battle these kind of threats outside of the simulator.

Global Defense Network is a sci-fi shooter game with rhythm elements. From
first-person, behind the defensive weapon, it’s up to the player to blast away
all the threats on the screen; usually in conjunction with the music being
played. Bonuses are obtained for direct hits, ricochets, destruction of
multiple targets, quick shots and more! As the scores go up, rankings can be
compared against other GDF Agents.