The 3rd Birthday

The 3rd Birthday is a third-person role-playing shooter co-developed by Square Enix's "1st Production Department" and HexaDrive, and published by Square Enix for the PlayStation Portable. It was released in Japan in 2010 and in North America and Europe in 2011. The game is both the third entry in the Parasite Eve video game series, based on the titular Japanese novel, and a spin-off, having only a loose connection to events from past games. The game features a third-person shooter-based combat system with role-playing mechanics. A key mechanic is the Overdive ability, which allows the player to possess pre-positioned human allies and inflict damage upon enemies.

The game takes place in 2013, a year after creatures known as the Twisted have appeared from beneath Manhattan and decimated the city. To fight back against the Twisted, an investigatory team called the Counter Twisted Investigation (CTI) is formed. Among their number is series protagonist Aya Brea, who was found unconscious and suffering amnesia two years before the game's events. Using her Overdive ability, Aya travels into the past to alter the outcome of battles against the Twisted. At the same time, Aya attempts to find out the origin of the Twisted and regain her memories.