From the Super Mario Wiki, the Mario encyclopedia
Samurai Slice is a microgame in 9-Volt and 18-Volt's mode in Game & Wario, Gamer. A standalone version of it is unlockable as a Cluck-A-Pop souvenir, titled BALLOON FIGHTER: Samurai Slice. The name is a reference to the Rhythm Heaven minigame of the same name.
The player takes control of The Wandering Samurai from the Rhythm Heaven series. Their objective is to slice the fish on the conveyor belt by slashing the sword on the correct beats.