
Armored Core: Project Phantasma serves as a standalone expansion to the original Armored Core, which debuted on the PlayStation in 1997. The game centers around arena-style combat, featuring ranked one-on-one duels against opposing pilots. Players build and modify a humanoid mech using modular components that influence speed, attack power, and energy consumption. It prioritizes mechanical customization and combat expertise over varied missions. The design and gameplay elements of Project Phantasma laid the groundwork for competitive features that would become key in future titles of the series.
The Raven (protagonist) is handed a strange assignment. A cryptic message instructs the player to break into a secretive underground facility known as Amber Crown, offering a substantial financial reward. Upon entering Amber Crown, the player meets Sumika Juutilainen, a fugitive from the mysterious Doomsday Organization (called the Wednesday Organization in Japan), the clandestine group running the facility. Sumika becomes the player's main client and ally throughout the mission in Amber Crown. As the player progresses through more assignments, a rivalry forms with an Armored Core pilot named Stinger, who works for the Doomsday Organization. Stinger becomes increasingly threatening as the secrets of Amber Crown are revealed, eventually leading to the discovery of Project Phantasma. A classified initiative by the Doomsday Organization, Project Phantasma is a weapon system capable of shifting the balance of power. Both Sumika and Stinger were test subjects for the project. Driven by a desire to harness the power of Phantasma, Stinger tries to turn it against the player. The player's growing success pushes Stinger to fuse with Phantasma and confront the player in a climactic battle. The player overcomes Stinger and dismantles the Phantasma project, resulting in the downfall of the Doomsday Organization.
| PS1 | December 4, 1997 |
| PSP | September 27, 2007 |
| PS3 | September 27, 2007 |



| Audio | Subtitles | Interface | |
|---|---|---|---|
| English (US) | ✓ | ||
| 日本語 | ✓ |