Gaia Crusaders is a 2D side-scrolling beat ’em up arcade game developed by Noise Factory and released in 1999. It is known for its fast-paced action, unique post-apocalyptic setting, and elemental magic system. 

Gameplay and Mechanics

The game is a traditional side-scrolling brawler with some unique twists: 

• Controls: Players have buttons for punching, kicking, jumping/blocking, and a special attack. A “super attack” that consumes a small amount of health can also be performed.
• Elemental Orbs: Enemies drop colored orbs, which the player collects. Pressing the special attack button uses these orbs in the order they were collected to unleash elemental magic.
• Combo System: The game features a fluid combo system, including the ability to dash by double-tapping a direction, which allows for juggling enemies.
• Co-op: The game supports two-player co-op, though friendly fire is present.
• Difficulty: Reviewers note the game is challenging, designed to take quarters like a classic arcade title. 

Characters

There are five characters available at the start, with two more unlockable, all with unique fighting styles and elemental affinities: 

Unlockable Characters: Two bosses, the demon Rob and the mutant Seiyen, become playable after a certain point in the game.

Jimi Isaak: An all-around fighter similar to Cody from Final Fight, with average stats.

Kohen: A fast and strong priestess who takes extra damage but can set enemies on fire with her rune attacks.

Koufu: A wizard with good defense and power, but slower speed.

Fred Sathal: A fast character known for acrobatic moves and energy blasts.

M-985: A fast robot with strong defense, but weaker attacks.