Phantomas Saga: Infinity is an unofficial game inspired by the 1986 title Phantomas. Players control the character Phantomas as he infiltrates an factory where androids are being manufactured, the same factory where he was made. It is owned by an ancient, evil civilization hiding in the Andromeda Nebula where it secretly steers the lives of all of the universe, such as ruining countries, steering wars and overthrowing kings. Phantomas gets inside through an assembly line and needs to destroy ten self-destruct devices. This story reverses the concept of the female android as the protagonist in the Phantomasa series by the same developer and shares its universe.
The player navigates Phantomas through single-screen rooms linked together both horizontally and vertically using the flip-screen mechanic, offering some freedom of exploration. He has no means to attack and needs to avoid hazards and enemies. The amount of devices activated is tracked through a Bolts counter in the HUD. Certain sections are locked and can only be opened by locating a key first. When the Bolts count reaches ten a pump is activated and a countdown timer is started. Phantomas then need to quickly escape the factory before time runs out and it explodes.
He starts with 125 health that is drained quickly as long as he remains in contact with an enemy or a hazard. Next to the regular movement there are actions for two types of jumps: a high one and a far one.