Triggerheart Exelica is a top-down shooter with an intriguing storyline set in a distant future where intelligent weapons called Trigger Hearts have been developed by humanity. These Trigger Hearts closely resemble humans and over time even develop unique personalities. The story begins when two remaining Trigger Hearts, Exelica and Crueltear, are summoned to quell a mysterious rebellion of military machines against their human creators.
The gameplay in Triggerheart Exelica is fast-paced and action-packed, with five stages of shooting mayhem. Players can choose between two Trigger Hearts: Exelica, who fires a wide fan of weak shots, or Crueltear, who fires a narrowly concentrated barrage of projectiles. However, the real power comes from the Anchor Shot, a weapon common to both models that allows the player to grab, swing, use as a shield, and hurl back enemy ships. The Anchor Shot is a tricky weapon to use, requiring the player to circle the joystick to give enemy ships more inertia while dodging enemy fire.
The game also features AI-adjusted boss difficulty level, which adjusts to the player's skill level, providing a challenge for both inexperienced and experienced players. In addition to the original Arcade mode, the home version of the game includes a Story mode with fully voiced cutscenes, additional endings, and bosses, as well as Arranged Mode, which is limited to Normal difficulty and serves as a challenge for the most skilled players.
The PS2 port of Triggerheart Exelica includes new features such as an opening movie, story mode, and CG sequences. The game also adds Faintear as a playable fighter and the Triggerheart Backupper C'r_na as a playable character.