Hot potato is a cool interpretation of the theme. I haven't really seen many games where "be in a favorable state when the timer reaches zero" is the main win condition. My main concern is that waiting until the timer almost reaches zero followed by passing the potato is a foolproof strategy, although that is partially alleviated by the speedrun timer. I believe that additional enemy types with their own strategies could take this game to the next level.
For instance, while I don't know whether it would actually make for good gameplay, if the player had to hold the potato for at least 1 second, but they couldn't hold it for more than 4 seconds, and enemies had a similar rule, it would start to get some puzzle dynamics, where you have to figure out when to pass it so that the enemy can't get an advantage.