Super Fly Swatter
From the Super Mario Wiki, the Mario encyclopedia
Super Fly Swatter is a microgame in 9-Volt and 18-Volt's mode in Game & Wario, Gamer, based on the Gnat Attack mode of Mario Paint. Like other microgames in the title, it has an individual Cluck-A-Pop souvenir, titled BALLOON FIGHTER: Super Fly Swatter.
The player's objective is to swat all the 20 gnats on-screen with their giant fly swatter.