In 2102 C.E., a giant asteroid enters Earth’s orbit, and inside is a horde of
aliens led by the entity Diadora, unleashing an invasion on mankind. Hiding
deep underground, the surviving rebels create three experimental robots,
Sophia, Calista and Dynamis, to combat Diadora’s army, the objective codenamed
“Operation ExZeus”. These three robots are humanity’s last hope.

ExZeus is an on-rails arcade shooter in a third-person perspective. The
player can move in all directions while progressing forward, shooting enemies
and collecting power-ups and gold. The player has the ability to lock onto
enemies and fire powerful missiles at them, and also has a laser (which
recharges by itself after every use) they can launch by holding down the fire
button. The player can also send out nuclear bombs that destroy all of the
enemies on screen, which can also be used to help with bosses.

At the end of every level, the player faces a boss. Before the fight begins, a
screen will display the weaknesses of that boss. Successfully defeating a boss
will bring the player to the item shop, where they can buy items to power up
their robot, and then proceed to the next level.