Junimo Kart is a game playable on the arcade machine in The Stardrop Saloon. It is initially locked and requires the Skull Key to play. An arcade machine of the game that you can place and play in your house will be sent to your mailbox if you beat all six levels of the Progress Mode.
In the game, you play as a Junimo in a cart moving to the right side of the screen. The only control you have over the cart is jumping, with the left mouse button. Along the way you will encounter gaps or railway ends will be encountered, which must be avoided by jumping. If you don't jump at the right time or fall through a gap, you will lose a life out of the three you have. When all lives are used, you will be set back to the first area. Upon death or after completing a stage, your lives will completely refill.
So far, there is no special background music playing when you play Junimo Kart.