Description taken from Sega Genesis version of this game

Designed by Treasure, a Japanese company created by former members of Konami, Gunstar Heroes is a frenetically paced platform shooter in the spirit of Konami's Contra series. Gunstar Heroes features large, anime-styled protagonists that can engage foes in either hand-to-hand combat or with guns. Colorful levels are home to multiple boss characters, many of which fill the screen in size and employ a number of special effects. Futuristic weapons are comprised of four energy types, such as fire or lightning, which can be combined with one another to create more powerful blasts. You'll hop inside a runaway mine cart, participate in a deadly board game, scale a flying battleship, and more throughout seven stages of play. Options include multiple difficulty settings, which influence the number and types of enemies you'll encounter, and a choice between free or fixed shots while shooting. Complete the game alone or team-up with a friend for simultaneous action on the same screen. ~ Scott Alan Marriott, All Game Guide