Gun Hazard is a side-scrolling shooter with strong RPG elements, and a spin-off of the Front Mission series. Gameplay is more than a little similar to Cybernator or Metal Warriors. The player moves between different stages on an area map. Once inside a stage, the player controls Albert and his wanzer as it moves left, right across the screen. The wanzer is able to jump, and attack with a primary and a special weapon. At any time during a stage, Albert can eject from his heavily armed wanzer to explore. Although vulnerable when outside, Albert is able to reach areas the wanzer cannot, in addition to being a smaller target and being able to jetpack indefinitely.

Money and experience are earned through the completion of mission objectives as well as the kill count of enemy wanzers. Additionally, Albert can recruit other characters through the normal course of the story, some of whom can be designated to support roles. These support characters when set can provide a variety of different cover fire abilities for Albert during his missions. They too gain experience and levels. Different weapons and armor can be found or bought. Essential components include the Booster ability which allows the wanzer to hover and increase its jumps, as well as the Dash ability which allows quick left-right movement by the wanzer.