The story in Karaoke Revolution w/ Microphone is pretty straightforward - you're given a list of songs to sing along with, and if you do well enough, you unlock new tracks and gain points. The game's goal is to have fun singing with your friends or family.
The gameplay in Karaoke Revolution w/ Microphone involves pressing buttons on the microphone to match the pitches and rhythms of the songs. You can also use the microphone to interact with the game's characters, adding a bit of personality to the experience.