Adventures of Marshal Marshmallow is a first-person side-scrolling shooter set in a cartoonish Wild West where the characters are shaped as marshmallows. The player controls Marshal Marshmallow as he tries to save each town. The screen scrolls horizontally automatically and the player taps the screen to shoot opponents that appear from windows and from behind or on top of buildings. There are also innocent people that pop up and need to be left alone. The gun needs to be reloaded regularly by tapping it on the left side of the screen. Objects such as barrels and crates can also be shot. Pick-ups include health, ammo and dynamite. There are four towns and three daylight settings.