After the defeat of the evil king, the kingdom of Wonder Land was a paradise...for a time. The peace was broken when a ferocious, fire-breathing dragon struck without warning and took over Wonder Land with a swarm of evil, monstrous henchmen, turning the once-peaceful land into the utterly chaotic Monster Land.
Unable to fight, the people now look to Wonder Boy. Realizing that he is Wonder Land's last hope, Wonder Boy sets out on an incredible journey to rid the country of the monsters and defeat the "invincible" evil dragon. Guide Wonder Boy through various environments and dungeons, and defeat enemies using Special Weapons and Spells.