Released in 2001, Progear (officially Progear no Arashi) is a landmark side-scrolling “bullet hell” shooter developed by Cave and published on the Capcom Play System II (CPS2) hardware. 

Core Gameplay & Mechanics

• Ship Selection: Players choose one of two pilots (Ring or Bolt) and one of three female gunners (Chain, Nail, or Rivet), each offering different shot patterns and movement speeds.
• Dual-Shot System: Tapping the button fires a “fighter” shot for fast movement; holding it locks the gunner’s fire and slows the ship for precision dodging.
• Scoring (Rings & Jewels): Destroying enemies with the fighter shot converts bullets into rings. Switching to the gunner shot then converts bullets into high-value jewels, creating a “risk vs. reward” loop of building and cashing in scores.
• Bullet Hell Style: Features dense, complex bullet patterns that often include “slowdown” effects, which are sometimes intentional to help players navigate tight spaces. 

Story & Setting

• Plot: Five elderly nobles, the Motoruin sages, achieved immortality and overthrew the government of the country of “Parts.” A group of children discovers the “Progear” engine technology and pilots biplanes to lead a revolution against the immortals.