The story of Raiden takes place in the year 2090, when a species of alien lifeforms known as the Crystals invaded Earth. The Crystals took control over most of Earth’s military hardware to use in the invasion. In response, the world organization known as Vanquish Crystal Defense (VCD) develops the Fighting Thunder attack craft, a cutting-edge weapon based on Crystal technology.
To survive against the invaders and fight back, VCD deploys Fighting Thunder as the only hope for humanity. Raiden is a vertically scrolling shoot ’em up game consisting of eight stages of increasing difficulty. In each stage, the player maneuvers the Fighting Thunder craft, engaging various enemies and avoiding their attacks. In cooperative play, both players can generate special projectiles that damage enemies by shooting the other player craft.
After completing the eighth and final stage, the player returns to the first stage with the difficulty increased. Collectible items include bombs, which cancel out enemy fire and deal damage over a wide area; weapon power-ups; and score-increasing medals. There are two bonus collectible items: the Miclus (a boss in Seibu Kaihatsu’s 1985 title Wiz) and a fairy that releases power-up items when the player dies.
When the player dies, the fighter’s shrapnel become projectiles that damage enemies. If all lives are lost during a gameplay session, the game is over unless players insert more credits into the arcade machine to continue playing. Upon continuing, the player will start at the last checkpoint reached.