Heavy Barrel is a run-and-gun action game released for the NES in Japan. Players likely control a character who moves through levels while shooting enemies.  The gameplay probably emphasizes fast-paced action and skillful use of weapons to survive waves of adversaries and clear each stage.  Specific details on its mechanics would necessitate further exploration of gaming information sources.  The developer of Heavy Barrel is likely to be found within Japanese game archives.

Heavy Barrel (Japan)

Hatris (USA)