On May 25, 1992, SNK and Takara released a sequel for the Neo-Geo. Takara also ported it to the Super NES in 1993. This sequel takes the original in a new direction by using three of the monsters from the original game as heroes in a side-scrolling beat 'em up. Geon, Astro Guy, and Woo are all upgraded to defend Earth against an alien threat led by a creature called Famardy. The game also features a 2-player competition mode.
Super Geon: Geon mutated into a spiky, vicious form.
Cyber Woo: A cybernetic version of Woo, possibly inspired by Mechanikong.
Atomic Guy: Astro Guy with a super-charged arsenal and bigger muscles.
Source: Wikipedia, "King of the Monsters", available under the CC-BY-SA License.