Mario Kart Tour; sort of looks like it already has multiplayer, but the real answer is more complicated than that.
In case anyone is wondering what comes after S tier in multiplayer rankings : r/MarioKartTour
Mario Kart Tour on X: The Kart Pro event is on in #MarioKartTour, challenging you to get a streak of three first-place wins in multiplayer races. It comes with a challenge card
Mario Kart Tour Gets An Update, But It's Not The Multiplayer Fans Are Crying Out For
Mario Kart Tour finally arrives on Android, and it's easily the worst game in the series
Mario Kart PC
Mario Kart Tour Guide: Characters, Tracks, Multiplayer and more
Does 'Mario Kart Tour' Have Multiplayer? It's Complicated
MARIO KART TOUR stumbles out of the gate, practices unsafe driving
The Beta For Mario Kart Tour Doesn't Seem To Include Proper Multiplayer Racing
How to Play Mario Kart Tour Multiplayer - GameRevolution
Mario Strikers: Battle League Football review: Verdict on gameplay, multiplayer customisation and more
Analyzing Mario Kart Tour's Biggest Update - Feature - Nintendo World Report
Mario Kart Tour' Multiplayer Gameplay Impressions - As Fun & Chaotic as It Should Be
Birdo Joins Mario Kart Tour's Holiday Event As A Playable Character